Sulfurized estolides and methods of making and using the same

ABSTRACT

Provided herein are compounds of the formula: 
                         
in which n is an integer equal to or greater than 1; m is an integer equal to or greater than 1; R 2  is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched; and R 1 , R 3 , and R 4 , independently for each occurrence, are selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, wherein at least one of R 1 , R 2 , R 3 , or R 4  is sulfurized or epoxidized. Also provided are compositions containing the compounds and methods of making both the compounds and compositions thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 61/498,499, filed Jun. 17, 2011, U.S. Provisional Patent Application No. 61/569,046, filed Dec. 9, 2011, and U.S. Provisional Patent Application No. 61/583,139, filed Jan. 4, 2012, which are incorporated herein by reference in their entireties for all purposes.

FIELD

The present disclosure relates to epoxidized estolides, sulfurized estolides, and methods of making the same. The estolides described herein may be suitable for use as lubricants, lubricant additives, and plasticizers.

BACKGROUND

Lubricant compositions may be modified to alter and/or improve the properties of the lubricant. For example, anti-wear additives may be used in lubricating compositions to provide reduced friction and/or extreme pressure protection. Similarly, plastics and plasticized compositions can be specifically formulated to meet desired characteristics. For example, plasticizers may be added to polymeric compositions to impart flexibility and pliability.

SUMMARY

Described herein are estolide compounds, estolide-containing compositions, and methods of making the same. In certain embodiments, such compounds and/or compositions may be useful as lubricants and additives.

In certain embodiments, the estolides comprise at least one compound of Formula I:

-   -   wherein     -   W¹, W², W³, W⁴, W⁵, W⁶, and W⁷, independently for each         occurrence, are selected from —CH₂—, —CH═CH—, —CHR₅—, and

-   -   R₅ is selected from a halogen and —S_(v)R₆, wherein v is an         integer selected from 1 to 8 and R₆ is selected from hydrogen         and an estolide residue;     -   T is selected from O and S;     -   z is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   p is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   q is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   x is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   y is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   n is equal to or greater than 0; and     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched,     -   wherein each fatty acid chain residue of said at least one         compound is independently optionally substituted, and     -   wherein at least one of W¹, W², W³, W⁴, W⁵, W⁶, and W⁷ is —CHR₅—         or

In certain embodiments, the estolides comprise at least one compound of Formula II:

-   -   wherein     -   m is an integer equal to or greater than 1;     -   n is an integer equal to or greater than 0;     -   R₁, independently for each occurrence, is an optionally         substituted alkyl that is saturated or unsaturated, branched or         unbranched;     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched;         and     -   R₃ and R₄, independently for each occurrence, are selected from         optionally substituted alkyl that is saturated or unsaturated,         and branched or unbranched,     -   wherein at least one of R₁, R₂, R₃, or R₄ is sulfurized or         epoxidized.

In certain embodiments, the estolides comprise at least one estolide compound of Formula III:

-   -   wherein     -   T is selected from O and S;     -   z is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   q is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   x is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   y is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   n is equal to or greater than 0; and     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched,     -   wherein each fatty acid chain residue of said at least one         compound is independently optionally substituted.

A process of producing a lubricant composition is also described. In certain embodiments, the process comprises:

-   -   selecting at least one estolide compound; and     -   sulfurizing at least a portion of the at least one estolide         compound.

A process of producing a plasticized composition is also described. In certain embodiments, the process comprises:

-   -   selecting at least one estolide compound;     -   epoxidizing at least a portion of the at least one estolide         compound; and     -   contacting at least one polymeric material with the epoxidized         estolide compound to provide a plasticized composition.

DETAILED DESCRIPTION

The use of lubricant and plasticizer compounds, and/or compositions may result in the dispersion of such fluids, compounds, and/or compositions in the environment. Petroleum base oils used in common lubricant and plasticized compositions, as well as additives, are typically non-biodegradable and can be toxic. The present disclosure provides for the preparation and use of lubricant and plasticized compositions comprising partially or fully bio-degradable compounds, including base oils comprising one or more estolides.

In certain embodiments, the compounds and/or compositions comprising one or more estolides are partially or fully biodegradable and thereby pose diminished risk to the environment. In certain embodiments, the compounds and/or compositions meet guidelines set for by the Organization for Economic Cooperation and Development (OECD) for degradation and accumulation testing. The OECD has indicated that several tests may be used to determine the “ready biodegradability” of organic chemicals. Aerobic ready biodegradability by OECD 301D measures the mineralization of the test sample to CO₂ in closed aerobic microcosms that simulate an aerobic aquatic environment, with microorganisms seeded from a waste-water treatment plant. OECD 301D is considered representative of most aerobic environments that are likely to receive waste materials. Aerobic “ultimate biodegradability” can be determined by OECD 302D. Under OECD 302D, microorganisms are pre-acclimated to biodegradation of the test material during a pre-incubation period, then incubated in sealed vessels with relatively high concentrations of microorganisms and enriched mineral salts medium. OECD 302D ultimately determines whether the test materials are completely biodegradable, albeit under less stringent conditions than “ready biodegradability” assays.

As used in the present specification, the following words, phrases and symbols are generally intended to have the meanings as set forth below, except to the extent that the context in which they are used indicates otherwise. The following abbreviations and terms have the indicated meanings throughout:

A dash (“-”) that is not between two letters or symbols is used to indicate a point of attachment for a substituent. For example, —C(O)NH₂ is attached through the carbon atom.

“Alkoxy” by itself or as part of another substituent refers to a radical —OR³¹ where R³¹ is alkyl, cycloalkyl, cycloalkylalkyl, aryl, or arylalkyl, which can be substituted, as defined herein. In some embodiments, alkoxy groups have from 1 to 8 carbon atoms. In some embodiments, alkoxy groups have 1, 2, 3, 4, 5, 6, 7, or 8 carbon atoms. Examples of alkoxy groups include, but are not limited to, methoxy, ethoxy, propoxy, butoxy, cyclohexyloxy, and the like.

“Alkyl” by itself or as part of another substituent refers to a saturated or unsaturated, branched, or straight-chain monovalent hydrocarbon radical derived by the removal of one hydrogen atom from a single carbon atom of a parent alkane, alkene, or alkyne. Examples of alkyl groups include, but are not limited to, methyl; ethyls such as ethanyl, ethenyl, and ethynyl; propyls such as propan-1-yl, propan-2-yl, prop-1-en-1-yl, prop-1-en-2-yl, prop-2-en-1-yl (allyl), prop-1-yn-1-yl, prop-2-yn-1-yl, etc.; butyls such as butan-1-yl, butan-2-yl, 2-methyl-propan-1-yl, 2-methyl-propan-2-yl, but-1-en-1-yl, but-1-en-2-yl, 2-methyl-prop-1-en-1-yl, but-2-en-1-yl, but-2-en-2-yl, buta-1,3-dien-1-yl, buta-1,3-dien-2-yl, but-1-yn-1-yl, but-1-yn-3-yl, but-3-yn-1-yl, etc.; and the like.

Unless otherwise indicated, the term “alkyl” is specifically intended to include groups having any degree or level of saturation, i.e., groups having exclusively single carbon-carbon bonds, groups having one or more double carbon-carbon bonds, groups having one or more triple carbon-carbon bonds, and groups having mixtures of single, double, and triple carbon-carbon bonds. Where a specific level of saturation is intended, the terms “alkanyl,” “alkenyl,” and “alkynyl” are used. In certain embodiments, an alkyl group comprises from 1 to 40 carbon atoms, in certain embodiments, from 1 to 22 or 1 to 18 carbon atoms, in certain embodiments, from 1 to 16 or 1 to 8 carbon atoms, and in certain embodiments from 1 to 6 or 1 to 3 carbon atoms. In certain embodiments, an alkyl group comprises from 8 to 22 carbon atoms, in certain embodiments, from 8 to 18 or 8 to 16. In some embodiments, the alkyl group comprises from 3 to 20 or 7 to 17 carbons. In some embodiments, the alkyl group comprises 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, or 22 carbon atoms.

“Aryl” by itself or as part of another substituent refers to a monovalent aromatic hydrocarbon radical derived by the removal of one hydrogen atom from a single carbon atom of a parent aromatic ring system. Aryl encompasses 5- and 6-membered carbocyclic aromatic rings, for example, benzene; bicyclic ring systems wherein at least one ring is carbocyclic and aromatic, for example, naphthalene, indane, and tetralin; and tricyclic ring systems wherein at least one ring is carbocyclic and aromatic, for example, fluorene. Aryl encompasses multiple ring systems having at least one carbocyclic aromatic ring fused to at least one carbocyclic aromatic ring, cycloalkyl ring, or heterocycloalkyl ring. For example, aryl includes 5- and 6-membered carbocyclic aromatic rings fused to a 5- to 7-membered non-aromatic heterocycloalkyl ring containing one or more heteroatoms chosen from N, O, and S. For such fused, bicyclic ring systems wherein only one of the rings is a carbocyclic aromatic ring, the point of attachment may be at the carbocyclic aromatic ring or the heterocycloalkyl ring. Examples of aryl groups include, but are not limited to, groups derived from aceanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene, hexylene, as-indacene, s-indacene, indane, indene, naphthalene, octacene, octaphene, octalene, ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene, triphenylene, trinaphthalene, and the like. In certain embodiments, an aryl group can comprise from 5 to 20 carbon atoms, and in certain embodiments, from 5 to 12 carbon atoms. In certain embodiments, an aryl group can comprise 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 carbon atoms. Aryl, however, does not encompass or overlap in any way with heteroaryl, separately defined herein. Hence, a multiple ring system in which one or more carbocyclic aromatic rings is fused to a heterocycloalkyl aromatic ring, is heteroaryl, not aryl, as defined herein.

“Arylalkyl” by itself or as part of another substituent refers to an acyclic alkyl radical in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with an aryl group. Examples of arylalkyl groups include, but are not limited to, benzyl, 2-phenylethan-1-yl, 2-phenylethen-1-yl, naphthylmethyl, 2-naphthylethan-1-yl, 2-naphthylethen-1-yl, naphthobenzyl, 2-naphthophenylethan-1-yl, and the like. Where specific alkyl moieties are intended, the nomenclature arylalkanyl, arylalkenyl, or arylalkynyl is used. In certain embodiments, an arylalkyl group is C₇₋₃₀ arylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the arylalkyl group is C₁₋₁₀ and the aryl moiety is C₆₋₂₀, and in certain embodiments, an arylalkyl group is C₇₋₂₀ arylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the arylalkyl group is C₁₋₈ and the aryl moiety is C₆₋₁₂.

Estolide “base oil” and “base stock”, unless otherwise indicated, refer to any composition comprising one or more estolide compounds. It should be understood that an estolide “base oil” or “base stock” is not limited to compositions for a particular use, and may generally refer to compositions comprising one or more estolides, including mixtures of estolides. Estolide base oils and base stocks can also include compounds other than estolides.

“Compounds” refers to compounds encompassed by structural Formula I, II, and III herein and includes any specific compounds within the formula whose structure is disclosed herein. Compounds may be identified either by their chemical structure and/or chemical name. When the chemical structure and chemical name conflict, the chemical structure is determinative of the identity of the compound. The compounds described herein may contain one or more chiral centers and/or double bonds and therefore may exist as stereoisomers such as double-bond isomers (i.e., geometric isomers), enantiomers, or diastereomers. Accordingly, any chemical structures within the scope of the specification depicted, in whole or in part, with a relative configuration encompass all possible enantiomers and stereoisomers of the illustrated compounds including the stereoisomerically pure form (e.g., geometrically pure, enantiomerically pure, or diastereomerically pure) and enantiomeric and stereoisomeric mixtures. Enantiomeric and stereoisomeric mixtures may be resolved into their component enantiomers or stereoisomers using separation techniques or chiral synthesis techniques well known to the skilled artisan.

For the purposes of the present disclosure, “chiral compounds” are compounds having at least one center of chirality (i.e. at least one asymmetric atom, in particular at least one asymmetric C atom), having an axis of chirality, a plane of chirality or a screw structure. “Achiral compounds” are compounds which are not chiral.

Compounds of Formula I, II, and III include, but are not limited to, optical isomers of compounds of Formula I, II, and III, racemates thereof, and other mixtures thereof. In such embodiments, the single enantiomers or diastereomers, i.e., optically active forms, can be obtained by asymmetric synthesis or by resolution of the racemates. Resolution of the racemates may be accomplished by, for example, chromatography, using, for example a chiral high-pressure liquid chromatography (HPLC) column. However, unless otherwise stated, it should be assumed that Formula I, II, and III cover all asymmetric variants of the compounds described herein, including isomers, racemates, enantiomers, diastereomers, and other mixtures thereof. In addition, compounds of Formula I, II and III include Z- and E-forms (e.g., cis- and trans-forms) of compounds with double bonds. The compounds of Formula I, II, and III may also exist in several tautomeric forms including the enol form, the keto form, and mixtures thereof. Accordingly, the chemical structures depicted herein encompass all possible tautomeric forms of the illustrated compounds.

“Cycloalkyl” by itself or as part of another substituent refers to a saturated or unsaturated cyclic alkyl radical. Where a specific level of saturation is intended, the nomenclature “cycloalkanyl” or “cycloalkenyl” is used. Examples of cycloalkyl groups include, but are not limited to, groups derived from cyclopropane, cyclobutane, cyclopentane, cyclohexane, and the like. In certain embodiments, a cycloalkyl group is C₃₋₁₅ cycloalkyl, and in certain embodiments, C₃₋₁₂ cycloalkyl or C₅₋₁₂ cycloalkyl. In certain embodiments, a cycloalkyl group is a C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, or C₁₅ cycloalkyl.

“Cycloalkylalkyl” by itself or as part of another substituent refers to an acyclic alkyl radical in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with a cycloalkyl group. Where specific alkyl moieties are intended, the nomenclature cycloalkylalkanyl, cycloalkylalkenyl, or cycloalkylalkynyl is used. In certain embodiments, a cycloalkylalkyl group is C₇₋₃₀ cycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the cycloalkylalkyl group is C₁₋₁₀ and the cycloalkyl moiety is C₆₋₂₀, and in certain embodiments, a cycloalkylalkyl group is C₇₋₂₀ cycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the cycloalkylalkyl group is C₁₋₈ and the cycloalkyl moiety is C₄₋₂₀ or C₆₋₁₂.

“Halogen” refers to a fluoro, chloro, bromo, or iodo group.

“Heteroaryl” by itself or as part of another substituent refers to a monovalent heteroaromatic radical derived by the removal of one hydrogen atom from a single atom of a parent heteroaromatic ring system. Heteroaryl encompasses multiple ring systems having at least one aromatic ring fused to at least one other ring, which can be aromatic or non-aromatic in which at least one ring atom is a heteroatom. Heteroaryl encompasses 5- to 12-membered aromatic, such as 5- to 7-membered, monocyclic rings containing one or more, for example, from 1 to 4, or in certain embodiments, from 1 to 3, heteroatoms chosen from N, O, and S, with the remaining ring atoms being carbon; and bicyclic heterocycloalkyl rings containing one or more, for example, from 1 to 4, or in certain embodiments, from 1 to 3, heteroatoms chosen from N, O, and S, with the remaining ring atoms being carbon and wherein at least one heteroatom is present in an aromatic ring. For example, heteroaryl includes a 5- to 7-membered heterocycloalkyl, aromatic ring fused to a 5- to 7-membered cycloalkyl ring. For such fused, bicyclic heteroaryl ring systems wherein only one of the rings contains one or more heteroatoms, the point of attachment may be at the heteroaromatic ring or the cycloalkyl ring. In certain embodiments, when the total number of N, S, and O atoms in the heteroaryl group exceeds one, the heteroatoms are not adjacent to one another. In certain embodiments, the total number of N, S, and O atoms in the heteroaryl group is not more than two. In certain embodiments, the total number of N, S, and O atoms in the aromatic heterocycle is not more than one. Heteroaryl does not encompass or overlap with aryl as defined herein.

Examples of heteroaryl groups include, but are not limited to, groups derived from acridine, arsindole, carbazole, β-carboline, chromane, chromene, cinnoline, furan, imidazole, indazole, indole, indoline, indolizine, isobenzofuran, isochromene, isoindole, isoindoline, isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine, phenanthroline, phenazine, phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and the like. In certain embodiments, a heteroaryl group is from 5- to 20-membered heteroaryl, and in certain embodiments from 5- to 12-membered heteroaryl or from 5- to 10-membered heteroaryl. In certain embodiments, a heteroaryl group is a 5-, 6-, 7-, 8-, 9-, 10-, 11-, 12-, 13-, 14-, 15-, 16-, 17-, 18-, 19-, or 20-membered heteroaryl. In certain embodiments heteroaryl groups are those derived from thiophene, pyrrole, benzothiophene, benzofuran, indole, pyridine, quinoline, imidazole, oxazole, and pyrazine.

“Heteroarylalkyl” by itself or as part of another substituent refers to an acyclic alkyl radical in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with a heteroaryl group. Where specific alkyl moieties are intended, the nomenclature heteroarylalkanyl, heteroarylalkenyl, or heteroarylalkynyl is used. In certain embodiments, a heteroarylalkyl group is a 6- to 30-membered heteroarylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the heteroarylalkyl is 1- to 10-membered and the heteroaryl moiety is a 5- to 20-membered heteroaryl, and in certain embodiments, 6- to 20-membered heteroarylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the heteroarylalkyl is 1- to 8-membered and the heteroaryl moiety is a 5- to 12-membered heteroaryl.

“Heterocycloalkyl” by itself or as part of another substituent refers to a partially saturated or unsaturated cyclic alkyl radical in which one or more carbon atoms (and any associated hydrogen atoms) are independently replaced with the same or different heteroatom. Examples of heteroatoms to replace the carbon atom(s) include, but are not limited to, N, P, O, S, Si, etc. Where a specific level of saturation is intended, the nomenclature “heterocycloalkanyl” or “heterocycloalkenyl” is used. Examples of heterocycloalkyl groups include, but are not limited to, groups derived from epoxides, azirines, thiiranes, imidazolidine, morpholine, piperazine, piperidine, pyrazolidine, pyrrolidine, quinuclidine, and the like.

“Heterocycloalkylalkyl” by itself or as part of another substituent refers to an acyclic alkyl radical in which one of the hydrogen atoms bonded to a carbon atom, typically a terminal or sp³ carbon atom, is replaced with a heterocycloalkyl group. Where specific alkyl moieties are intended, the nomenclature heterocycloalkylalkanyl, heterocycloalkylalkenyl, or heterocycloalkylalkynyl is used. In certain embodiments, a heterocycloalkylalkyl group is a 6- to 30-membered heterocycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the heterocycloalkylalkyl is 1- to 10-membered and the heterocycloalkyl moiety is a 5- to 20-membered heterocycloalkyl, and in certain embodiments, 6- to 20-membered heterocycloalkylalkyl, e.g., the alkanyl, alkenyl, or alkynyl moiety of the heterocycloalkylalkyl is 1- to 8-membered and the heterocycloalkyl moiety is a 5- to 12-membered heterocycloalkyl.

“Mixture” refers to a collection of molecules or chemical substances. Each component in a mixture can be independently varied. A mixture may contain, or consist essentially of, two or more substances intermingled with or without a constant percentage composition, wherein each component may or may not retain its essential original properties, and where molecular phase mixing may or may not occur. In mixtures, the components making up the mixture may or may not remain distinguishable from each other by virtue of their chemical structure.

“Parent aromatic ring system” refers to an unsaturated cyclic or polycyclic ring system having a conjugated π (pi) electron system. Included within the definition of “parent aromatic ring system” are fused ring systems in which one or more of the rings are aromatic and one or more of the rings are saturated or unsaturated, such as, for example, fluorene, indane, indene, phenalene, etc. Examples of parent aromatic ring systems include, but are not limited to, aceanthrylene, acenaphthylene, acephenanthrylene, anthracene, azulene, benzene, chrysene, coronene, fluoranthene, fluorene, hexacene, hexaphene, hexylene, as-indacene, s-indacene, indane, indene, naphthalene, octacene, octaphene, octalene, ovalene, penta-2,4-diene, pentacene, pentalene, pentaphene, perylene, phenalene, phenanthrene, picene, pleiadene, pyrene, pyranthrene, rubicene, triphenylene, trinaphthalene, and the like.

“Parent heteroaromatic ring system” refers to a parent aromatic ring system in which one or more carbon atoms (and any associated hydrogen atoms) are independently replaced with the same or different heteroatom. Examples of heteroatoms to replace the carbon atoms include, but are not limited to, N, P, O, S, Si, etc. Specifically included within the definition of “parent heteroaromatic ring systems” are fused ring systems in which one or more of the rings are aromatic and one or more of the rings are saturated or unsaturated, such as, for example, arsindole, benzodioxan, benzofuran, chromane, chromene, indole, indoline, xanthene, etc. Examples of parent heteroaromatic ring systems include, but are not limited to, arsindole, carbazole, β-carboline, chromane, chromene, cinnoline, furan, imidazole, indazole, indole, indoline, indolizine, isobenzofuran, isochromene, isoindole, isoindoline, isoquinoline, isothiazole, isoxazole, naphthyridine, oxadiazole, oxazole, perimidine, phenanthridine, phenanthroline, phenazine, phthalazine, pteridine, purine, pyran, pyrazine, pyrazole, pyridazine, pyridine, pyrimidine, pyrrole, pyrrolizine, quinazoline, quinoline, quinolizine, quinoxaline, tetrazole, thiadiazole, thiazole, thiophene, triazole, xanthene, and the like.

“Substituted” refers to a group in which one or more hydrogen atoms are independently replaced with the same or different substituent(s). Examples of substituents include, but are not limited to, —R⁶⁴, —R⁶⁰, —O⁻, —OH, ═O, —OR⁶⁰, —SR⁶⁰, —S⁻, ═S, —NR⁶⁰R⁶¹, ═NR⁶⁰, —CN, —CF₃, —OCN, —SCN, —NO, —NO₂, ═N₂, —N₃, —S(O)₂O⁻, —S(O)₂OH, —S(O)₂R⁶⁰, —OS(O₂)O⁻, —OS(O)₂R⁶⁰, —P(O)(O⁻)₂, —P(O)(OR⁶⁰)(O⁻), —OP(O)(OR⁶⁰)(OR⁶¹), —C(O)R⁶⁰, —C(S)R⁶⁰, —C(O)OR⁶⁰, —C(O)NR⁶⁰R⁶¹, —C(O)O⁻, —C(S)OR⁶⁰, —NR⁶²C(O)NR⁶⁰R⁶¹, —NR⁶²C(S)NR⁶⁰R⁶¹, —NR⁶²C(NR⁶³NR⁶⁰R⁶¹, —C(NR⁶²)NR⁶OR⁶¹, —S(O)₂, NR⁶⁰R⁶¹, —NR⁶³S(O)₂R⁶⁰, —NR⁶³C(O)R⁶⁰, and —S(O)R⁶⁰;

wherein each —R⁶⁴ is independently a halogen; each R⁶⁰ and R⁶¹ are independently alkyl, substituted alkyl, alkoxy, substituted alkoxy, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl, arylalkyl, substituted arylalkyl, heteroarylalkyl, or substituted heteroarylalkyl, or R⁶⁰ and R⁶¹ together with the nitrogen atom to which they are bonded form a heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, or substituted heteroaryl ring, and R⁶² and R⁶³ are independently alkyl, substituted alkyl, aryl, substituted aryl, arylalkyl, substituted arylalkyl, cycloalkyl, substituted cycloalkyl, heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, substituted heteroaryl, heteroarylalkyl, or substituted heteroarylalkyl, or R⁶² and R⁶³ together with the atom to which they are bonded form one or more heterocycloalkyl, substituted heterocycloalkyl, heteroaryl, or substituted heteroaryl rings;

wherein the “substituted” substituents, as defined above for R⁶⁰, R⁶¹, R⁶², and R⁶³, are substituted with one or more, such as one, two, or three, groups independently selected from alkyl, -alkyl-OH, —O-haloalkyl, -alkyl-NH₂, alkoxy, cycloalkyl, cycloalkylalkyl, heterocycloalkyl, heterocycloalkylalkyl, aryl, heteroaryl, arylalkyl, heteroarylalkyl, —O⁻, —OH, ═O, —O-alkyl, —O-aryl, —O-heteroarylalkyl, —O-cycloalkyl, —O-heterocycloalkyl, —SH, —S⁻, ═S, —S-alkyl, —S-aryl, —S-heteroarylalkyl, —S-cycloalkyl, —S-heterocycloalkyl, —NH₂, ═NH, —CN, —CF₃, —OCN, —SCN, —NO, —NO₂, ═N₂, —N₃, —S(O)₂O⁻, —S(O)₂, —S(O)₂OH, —OS(O₂)O⁻, —SO₂(alkyl), —SO₂(phenyl), —SO₂(haloalkyl), —SO₂NH₂, —SO₂NH(alkyl), —SO₂NH(phenyl), —P(O)(O)₂, —P(O)(O-alkyl)(O⁻), —OP(O)(O-alkyl)(O-alkyl), —CO₂H, —C(O)O(alkyl), —CON(alkyl)(alkyl), —CONH(alkyl), —CONH₂, —C(O)(alkyl), —C(O)(phenyl), —C(O)(haloalkyl), —OC(O)(alkyl), —N(alkyl)(alkyl), —NH(alkyl), —N(alkyl)(alkylphenyl), —NH(alkylphenyl), —NHC(O)(alkyl), —NHC(O)(phenyl), —N(alkyl)C(O)(alkyl), and —N(alkyl)C(O)(phenyl).

As used in this specification and the appended claims, the articles “a,” “an,” and “the” include plural referents unless expressly and unequivocally limited to one referent.

The term “fatty acid” refers to any natural or synthetic carboxylic acid comprising an alkyl chain that may be saturated, monounsaturated, or polyunsaturated, and may have straight or branched chains. The fatty acid may also be substituted. “Fatty acid,” as used herein, includes short chain alkyl carboxylic acid including, for example, acetic acid, propionic acid, etc.

All numerical ranges herein include all numerical values and ranges of all numerical values within the recited range of numerical values.

The present disclosure relates to estolide compounds, compositions and methods of making the same. In certain embodiments, the present disclosure also relates to estolide compounds, compositions comprising estolide compounds, the synthesis of such compounds, and the formulation of such compositions. In certain embodiments, the present disclosure relates to biosynthetic estolides having desired viscometric properties, while retaining or even improving other properties such as oxidative stability and pour point. In certain embodiments, new methods of preparing estolide compounds exhibiting such properties are provided. The present disclosure also relates to compositions comprising certain estolide compounds exhibiting such properties.

In certain embodiments, the estolides comprise at least one compound of Formula I:

-   -   wherein     -   W¹, W², W³, W⁴, W⁵, W⁶, and W⁷, independently for each         occurrence, are selected from —CH₂—, —CH═CH—, —CHR₅—, and

-   -   R₅ is selected from a halogen and —S_(v)R₆, wherein v is an         integer selected from 1 to 8 and R₆ is selected from hydrogen         and an estolide residue;     -   T is selected from O and S;     -   z is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   p is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   q is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   x is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   y is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   n is equal to or greater than 0; and     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched,     -   wherein each fatty acid chain residue of said at least one         compound is independently optionally substituted, and     -   wherein at least one of W¹, W², W³, W⁴, W⁵, W⁶, and W⁷ is —CHR₅—         or

In certain embodiments, the estolides comprise at least one compound of Formula II:

-   -   wherein     -   m is an integer equal to or greater than 1;     -   n is an integer equal to or greater than 0;     -   R₁, independently for each occurrence, is an optionally         substituted alkyl that is saturated or unsaturated, branched or         unbranched;     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched;         and     -   R₃ and R₄, independently for each occurrence, are selected from         optionally substituted alkyl that is saturated or unsaturated,         and branched or unbranched,     -   wherein at least one of R₁, R₂, R₃, or R₄ is epoxidized or         sulfurized.

In certain embodiments, the estolides comprise at least one compound of Formula III:

-   -   wherein     -   T is selected from O and S;     -   z is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   q is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10,         11, 12, 13, 14, and 15;     -   x is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   y is, independently for each occurrence, an integer selected         from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,         17, 18, 19, and 20;     -   n is equal to or greater than 0; and     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched,     -   wherein each fatty acid chain residue of said at least one         compound is independently optionally substituted.

The terms “chain” or “fatty acid chain” or “fatty acid chain residue,” as used with respect to the estolide compounds of Formula I, II, and III, refer to one or more of the fatty acid residues incorporated in estolide compounds, e.g., R₃ or R₄ of Formula II, the structures represented by

and CH₃(CH₂)_(y)CH(CH₂)—C(O)O— in Formula III, or the structures represented by CH₃(W¹)_(q)CH₂(W²)_(p)CH₂(W³)_(z)—C(O)—O—, CH₃(W⁴)_(y)CH₂(W⁵)_(x)—C(O)—O—, and CH₃(W⁶)_(y)CH₂(W⁷)_(x)—C(O)—O— in Formula I.

The R₁ of Formula II is an example of what may be referred to as a “cap” or “capping material,” as it “caps” the top of the estolide. For example, the capping group may be an organic acid residue of general formula CH₃(W¹)_(q)CH₂(W²)_(p)CH₂(W³)_(z)—C(O)—O—, i.e., as reflected in Formula I. In certain embodiments, the “cap” or “capping group” is a fatty acid. In certain embodiments, the capping group, regardless of size, is substituted or unsubstituted, saturated or unsaturated, and/or branched or unbranched. For example, in certain embodiments, the cap is epoxidized or sulfurized, and is thus substituted with at least one oxygen or at least one sulfur, respectively. The cap or capping material may also be referred to as the primary or alpha (α) chain.

Depending on the manner in which the estolide is synthesized, the cap or capping group alkyl may be the only alkyl from an organic acid residue in the resulting estolide that is unsaturated. In certain embodiments, it may be desirable to use a saturated organic or fatty-acid cap to increase the overall saturation of the estolide and/or to increase the resulting estolide's stability. For example, in certain embodiments, it may be desirable to provide a method of providing a saturated capped estolide by epoxidizing, sulfurizing, and/or hydrogenating an unsaturated cap using any suitable methods available to those of ordinary skill in the art. Epoxidizing, sulfurizing, and/or hydrogenating may be used with various sources of the fatty-acid feedstock, which may include mono- and/or polyunsaturated fatty acids. Without being bound to any particular theory, in certain embodiments, epoxidizing the estolide may help to improve the solubility and/or miscibility of the compound in certain compositions, such as those containing polymeric materials. Without being bound to any particular theory, in certain embodiments, sulfurizing the estolide may help to improve the frictional properties of the compound, and thus may be useful in providing wear and extreme pressure properties to lubricant compositions. Without being bound to any particular theory, in certain embodiments, hydrogenating the estolide may help to improve the overall stability of the molecule. However, a fully-hydrogenated estolide, such as an estolide with a larger fatty acid cap, may exhibit increased pour point temperatures. In certain embodiments, it may be desirable to offset any loss in desirable pour-point characteristics by using shorter, saturated capping materials.

The R₄C(O)O— of Formula II, the structure CH₃(W⁶)_(y)CH(W⁷)—C(O)O— of Formula I, or the structure CH₃(CH₂)_(y)CH(CH₂)—C(O)O— of Formula III serve as the “base” or “base chain residue” of the estolide. Depending on the manner in which the estolide is synthesized, the base organic acid or fatty acid residue may be the only residue that remains in its free-acid form after the initial synthesis of the estolide. However, in certain embodiments, in an effort to alter or improve the properties of the estolide, the free acid may be reacted with any number of substituents. For example, it may be desirable to react the free acid estolide with alcohols, glycols, amines, or other suitable reactants to provide the corresponding ester, amide, or other reaction products. The base or base chain residue may also be referred to as tertiary or gamma (γ) chains.

The R₃C(O)O— of Formula II, CH₃(CH₂)_(y)CH(CH₂)—C(O)O— of Formula III, and CH₃(W⁴)_(y)CH(W⁵)—C(O)O— of Formula I are linking residues that link the capping material and the base fatty-acid residue together. There may be any number of linking residues in the estolide, including when n=0 and the estolide is in its dimer form. Depending on the manner in which the estolide is prepared, a linking residue may be a fatty acid and may initially be in an unsaturated form during synthesis. In some embodiments, the estolide will be formed when a catalyst is used to produce a carbocation at the fatty acid's site of unsaturation, which is followed by nucleophilic attack on the carbocation by the carboxylic group of another fatty acid. In some embodiments, it may be desirable to have a linking fatty acid that is monounsaturated so that when the fatty acids link together, all of the sites of unsaturation are eliminated. The linking residue(s) may also be referred to as secondary or beta (β) chains.

In certain embodiments, the linking residues present in an estolide differ from one another. In certain embodiments, one or more of the linking residues differs from the base chain residue.

As noted above, in certain embodiments, suitable unsaturated fatty acids for preparing the estolides may include any mono- or polyunsaturated fatty acid. For example, monounsaturated fatty acids, along with a suitable catalyst, will form a single carbocation that allows for the addition of a second fatty acid, whereby a single link between two fatty acids is formed. Suitable monounsaturated fatty acids may include, but are not limited to, palmitoleic acid (16:1), vaccenic acid (18:1), oleic acid (18:1), eicosenoic acid (20:1), erucic acid (22:1), and nervonic acid (24:1). In addition, in certain embodiments, polyunsaturated fatty acids may be used to create estolides. Suitable polyunsaturated fatty acids may include, but are not limited to, hexadecatrienoic acid (16:3), alpha-linolenic acid (18:3), stearidonic acid (18:4), eicosatrienoic acid (20:3), eicosatetraenoic acid (20:4), eicosapentaenoic acid (20:5), heneicosapentaenoic acid (21:5), docosapentaenoic acid (22:5), docosahexaenoic acid (22:6), tetracosapentaenoic acid (24:5), tetracosahexaenoic acid (24:6), linoleic acid (18:2), gamma-linoleic acid (18:3), eicosadienoic acid (20:2), dihomo-gamma-linolenic acid (20:3), arachidonic acid (20:4), docosadienoic acid (20:2), adrenic acid (22:4), docosapentaenoic acid (22:5), tetracosatetraenoic acid (22:4), tetracosapentaenoic acid (24:5), pinolenic acid (18:3), podocarpic acid (20:3), rumenic acid (18:2), alpha-calendic acid (18:3), beta-calendic acid (18:3), jacaric acid (18:3), alpha-eleostearic acid (18:3), beta-eleostearic (18:3), catalpic acid (18:3), punicic acid (18:3), rumelenic acid (18:3), alpha-parinaric acid (18:4), beta-parinaric acid (18:4), and bosseopentaenoic acid (20:5). In certain embodiments, hydroxy fatty acids may be polymerized or homopolymerized by reacting the carboxylic acid functionality of one fatty acid with the hydroxy functionality of a second fatty acid. Exemplary hydroxyl fatty acids include, but are not limited to, ricinoleic acid, 6-hydroxystearic acid, 9,10-dihydroxystearic acid, 12-hydroxystearic acid, and 14-hydroxystearic acid.

The process for preparing the estolide compounds described herein may include the use of any natural or synthetic fatty acid source. However, it may be desirable to source the fatty acids from a renewable biological feedstock. Suitable starting materials of biological origin may include plant fats, plant oils, plant waxes, animal fats, animal oils, animal waxes, fish fats, fish oils, fish waxes, algal oils and mixtures thereof. Other potential fatty acid sources may include waste and recycled food-grade fats and oils, fats, oils, and waxes obtained by genetic engineering, fossil fuel-based materials and other sources of the materials desired.

In certain embodiments, the estolide compounds described herein may be prepared from non-naturally occurring fatty acids derived from naturally occurring feedstocks. In certain embodiments, the estolides are prepared from synthetic fatty acid reactants derived from naturally occurring feedstocks such as vegetable oils. For example, the synthetic fatty acid reactants may be prepared by cleaving fragments from larger fatty acid residues occurring in natural oils such as triglycerides using, for example, a cross-metathesis catalyst and alpha-olefin(s). The resulting truncated fatty acid residue(s) may be liberated from the glycerine backbone using any suitable hydrolytic and/or transesterification processes known to those of skill in the art. An exemplary fatty acid reactant includes 9-dodecenoic acid, which may be prepared via the cross metathesis of an oleic acid residue with 1-butene.

In certain embodiments, the estolide comprises fatty-acid chains of varying lengths. In some embodiments, z, p, and q are integers independently selected from 0 to 15, 0 to 12, 0 to 8, 0 to 6, 0 to 4, and 0 to 2. For example, in some embodiments, z is an integer selected from 0 to 15, 0 to 12, and 0 to 8. In some embodiments, z is an integer selected from 2 to 8. In some embodiments, z is 6. In some embodiments, p is an integer selected from 0 to 15, 0 to 6, and 0 to 3. In some embodiments, p is an integer selected from 1 to 5. In some embodiments, p is an integer selected from 1, 2, and 3, or 4, 5, and 6. In some embodiments, p is 1. In some embodiments, q is an integer selected from 0 to 15, 0 to 10, 0 to 6, and 0 to 3. In some embodiments, q is an integer selected from 1 to 8. In some embodiments, q is an integer selected from 0 and 1, 2 and 3, or 5 and 6. In some embodiments, q is 6. In some embodiments, z, p and q, independently for each occurrence, are selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 and 15. In some embodiments, z+p+q is an integer selected from 12 to 20. In some embodiments, z+p+q is 14. In some embodiments, z+p+q is 13.

In some embodiments, the estolide comprises fatty-acid chains of varying lengths. In some embodiments, x is, independently for each occurrence, an integer selected from 0 to 20, 0 to 18, 0 to 16, 0 to 14, 1 to 12, 1 to 10, 2 to 8, 6 to 8, or 4 to 6. In some embodiments, x is, independently for each occurrence, an integer selected from 7 and 8. In some embodiments, x is, independently for each occurrence, an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. In certain embodiments, for at least one fatty acid chain residue, x is an integer selected from 7 and 8.

In some embodiments, y is, independently for each occurrence, an integer selected from 0 to 20, 0 to 18, 0 to 16, 0 to 14, 1 to 12, 1 to 10, 2 to 8, 6 to 8, or 4 to 6. In some embodiments, y is, independently for each occurrence, an integer selected from 7 and 8. In some embodiments, y is, independently for each occurrence, an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. In some embodiments, for at least one fatty acid chain residue, y is an integer selected from 0 to 6, or 1 and 2. In certain embodiments, y is, independently for each occurrence, an integer selected from 1 to 6, or 1 and 2.

In some embodiments, x+y is, independently for each chain, an integer selected from 0 to 40, 0 to 20, 10 to 20, or 12 to 18. In some embodiments, x+y is, independently for each chain, an integer selected from 13 to 15. In some embodiments, x+y is 15 for each chain. In some embodiments, x+y is, independently for each chain, an integer selected from 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, and 24. In certain embodiments, for at least one fatty acid chain residue, x+y is an integer selected from 9 to 13. In certain embodiments, for at least one fatty acid chain residue, x+y is 9. In certain embodiments, x+y is, independently for each chain, an integer selected from 9 to 13. In certain embodiments, x+y is 9 for each fatty acid chain residue.

In some embodiments, W¹, W², W³, W⁴, W⁵, W⁶, and W⁷, independently for each occurrence, are selected from —CH₂—, —CH═CH—, —CHR₅—, and

wherein T is selected from O and S, R₅ is selected from a halogen and —S_(v)R₆, v is an integer selected from 1 to 8, and R₆ is selected from hydrogen and an estolide residue. As used herein, the term “estolide residue” refers to a portion of the same estolide molecule, or a portion of a different estolide molecule, to which one or more groups are bound. For example, in certain embodiments where the group W² for a compound of Formula I is the group —CHR₅—, and R₅ is —S_(v)R₆, the group R₆ may represent a second estolide molecule that is covalently bound to the group —S_(v)— (sulfide group), wherein the resulting structure comprises:

Alternatively, the R₆ group may represent the same estolide molecule, wherein the sulfide group provides an intramolecular linkage within the estolide molecule itself (e.g., —S_(v)— linkage between two fatty acid residue chains, such as between W² and W⁴), wherein the resulting structure comprises:

In certain embodiments, when a compound of Formula I comprises more than one —CHR₅—, said compound may comprise a combination of the prior examples and, e.g., may exhibit one or more intramolecular and/or intermolecular sulfide linkages.

In certain embodiments, W³ is —CH₂—. In certain embodiments, W¹ is —CH₂—. In certain embodiments, W³, W⁵, and W⁷ for each occurrence are —CH₂—. In some embodiments, W⁴ and W⁶ for each occurrence are —CH₂—. In certain embodiments, at least one of W¹, W², W³, W⁴, W⁵, W⁶, or W⁷ is selected from

In certain embodiments, W² is selected from —CHR₅— and

In certain embodiments, v is, independently for each occurrence, an integer selected from 1 and 2. In certain embodiments, W² is selected from

W¹, W³, W⁴, W⁵, and W⁶ are CH₂, x+y is 15 for each chain, z is 6, and q is 6.

In some embodiments, the estolide compound of Formula I, II, or III may comprise any number of fatty acid residues to form an “n-mer” estolide. For example, the estolide may be in its dimer (n=0), trimer (n=1), tetramer (n=2), pentamer (n=3), hexamer (n=4), heptamer (n=5), octamer (n=6), nonamer (n=7), or decamer (n=8) form. In some embodiments, n is an integer selected from 0 to 20, 0 to 18, 0 to 16, 0 to 14, 0 to 12, 0 to 10, 0 to 8, or 0 to 6. In some embodiments, n is an integer selected from 0 to 4. In some embodiments, n is 1, wherein said at least one compound of Formula I, II, or III comprises the trimer. In some embodiments, n is greater than 1. In some embodiments, n is an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20.

In certain embodiments, the compounds of Formulas I and III represent subgenera of Formula II. Thus, in some embodiments, reference to a compound of Formulas I or III may also be described in reference to Formula II. By way of example, a compound of Formula I can be described with reference to Formula II, wherein m=1 and R₄ represents the group CH₃(W¹)_(q)CH₂(W²)_(p)CH₂(W³)_(z)—.

In addition to being sulfurized and/or epoxidized, in certain embodiments, the capping group is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. In some embodiments, the alkyl group is a C₁ to C₄₀ alkyl, C₁ to C₂₂ alkyl or C₁ to C₁₈ alkyl. In some embodiments, the alkyl group is selected from C₇ to C₁₇ alkyl. For example, with reference to Formula II, in certain embodiments R₁ is selected from C₇ alkyl, C₉ alkyl, C₁₁ alkyl, C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₁ is selected from C₁₃ to C₁₇ alkyl, such as from C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₁ is a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ alkyl.

In some embodiments, R₂ of Formula I, II, or III is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. In some embodiments, the alkyl group is a C₁ to C₄₀ alkyl, C₁ to C₂₂ alkyl or C₁ to C₁₈ alkyl. In some embodiments, the alkyl group is selected from C₇ to C₁₇ alkyl. In some embodiments, R₂ is selected from C₇ alkyl, C₉ alkyl, C₁₁ alkyl, C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₂ is selected from C₁₃ to C₁₇ alkyl, such as from C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₂ is a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ alkyl.

In some embodiments, R₃ is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. In some embodiments, the alkyl group is a C₁ to C₄₀ alkyl, C₁ to C₂₂ alkyl or C₁ to C₁₈ alkyl. In some embodiments, the alkyl group is selected from C₇ to C₁₇ alkyl. In some embodiments, R₃ is selected from C₇ alkyl, C₉ alkyl, C₁₁ alkyl, C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₃ is selected from C₁₃ to C₁₇ alkyl, such as from C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₃ is a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ alkyl.

In some embodiments, R₄ is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. In some embodiments, the alkyl group is a C₁ to C₄₀ alkyl, C₁ to C₂₂ alkyl or C₁ to C₁₈ alkyl. In some embodiments, the alkyl group is selected from C₇ to C₁₇ alkyl. In some embodiments, R₄ is selected from C₇ alkyl, C₉ alkyl, C₁₁ alkyl, C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₄ is selected from C₁₃ to C₁₇ alkyl, such as from C₁₃ alkyl, C₁₅ alkyl, and C₁₇ alkyl. In some embodiments, R₄ is a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ alkyl.

As noted above, in certain embodiments, it may be possible to manipulate one or more of the estolides' properties by altering the length of R₁ and/or its degree of saturation. However, in certain embodiments, the level of substitution on R₁ may also be altered to change or even improve the estolides' properties. Without being bound to any particular theory, in certain embodiments, it is believed that the presence of polar substituents on R₁, such as one or more hydroxy groups, may increase the viscosity of the estolide, while increasing pour point. Accordingly, in some embodiments, R₁ will be unsubstituted or optionally substituted with a group that is not hydroxyl. Alternatively, in some embodiments, it may be desirable to increase the overall polarity of the molecule by providing one or more polar substituents on R₁, such as one or more epoxy groups, sulfur groups, and/or hydroxyl groups.

In some embodiments, the estolide is in its free-acid form, wherein R₂ of Formula I, II, or III is hydrogen. In some embodiments, R₂ is selected from optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched. In certain embodiments, the R₂ residue may comprise any desired alkyl group, such as those derived from esterification of the estolide with the alcohols identified in the examples herein. In some embodiments, the alkyl group is selected from C₁ to C₄₀, C₁ to C₂₂, C₃ to C₂₀, C₁ to C₁₈, or C₆ to C₁₂ alkyl. In some embodiments, R₂ may be selected from C₃ alkyl, C₄ alkyl, C₈ alkyl, C₁₂ alkyl, C₁₆ alkyl, C₁₈ alkyl, and C₂₀ alkyl. For example, in certain embodiments, R₂ may be branched, such as isopropyl, isobutyl, or 2-ethylhexyl. In some embodiments, R₂ may be a larger alkyl group, branched or unbranched, comprising C₁₂ alkyl, C₁₆ alkyl, C₁₈ alkyl, or C₂₀ alkyl. Such groups at the R₂ position may be derived from esterification of the free-acid estolide using the Jarcol™ line of alcohols marketed by Jarchem Industries, Inc. of Newark, N.J., including Jarcol™ I-18CG, I-20, I-12, I-16, I-18T, and 85BJ. In some cases, R₂ may be sourced from certain alcohols to provide branched alkyls such as isostearyl and isopalmityl. It should be understood that such isopalmityl and isostearyl alkyl groups may cover any branched variation of C₁₆ and C₁₈, respectively. For example, the estolides described herein may comprise highly-branched isopalmityl or isostearyl groups at the R₂ position, derived from the Fineoxocol® line of isopalmityl and isostearyl alcohols marketed by Nissan Chemical America Corporation of Houston, Tex., including Fineoxocol® 180, 180N, and 1600. Without being bound to any particular theory, in embodiments, large, highly-branched alkyl groups (e.g., isopalmityl and isostearyl) at the R₂ position of the estolides can provide at least one way to increase the lubricant's viscosity, while substantially retaining or even reducing its pour point.

In some embodiments, the compounds described herein may comprise a mixture of two or more estolide compounds of Formula I, II, and III. It is possible to characterize the chemical makeup of an estolide, a mixture of estolides, or a composition comprising estolides, by using the compound's, mixture's, or composition's measured estolide number (EN) of compound or composition. The EN represents the average number of fatty acids added to the base fatty acid. The EN also represents the average number of estolide linkages per molecule: EN=n+1 wherein n is the number of secondary (β) fatty acids. Accordingly, a single estolide compound will have an EN that is a whole number, for example for dimers, trimers, and tetramers: dimer EN=1 trimer EN=2 tetramer EN=3

However, a composition comprising two or more estolide compounds may have an EN that is a whole number or a fraction of a whole number. For example, a composition having a 1:1 molar ratio of dimer and trimer would have an EN of 1.5, while a composition having a 1:1 molar ratio of tetramer and trimer would have an EN of 2.5.

In some embodiments, the compositions may comprise a mixture of two or more estolides having an EN that is an integer or fraction of an integer that is greater than 4.5, or even 5.0. In some embodiments, the EN may be an integer or fraction of an integer selected from about 1.0 to about 5.0. In some embodiments, the EN is an integer or fraction of an integer selected from 1.2 to about 4.5. In some embodiments, the EN is selected from a value greater than 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6 and 5.8. In some embodiments, the EN is selected from a value less than 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, and 5.0, 5.2, 5.4, 5.6, 5.8, and 6.0. In some embodiments, the EN is selected from 1, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, 3.8, 4.0, 4.2, 4.4, 4.6, 4.8, 5.0, 5.2, 5.4, 5.6, 5.8, and 6.0.

As noted above, it should be understood that the chains of the estolide compounds may be independently optionally substituted, wherein one or more hydrogens are removed and replaced with one or more of the substituents identified herein. Similarly, two or more of the hydrogen residues may be removed to provide one or more sites of unsaturation, such as a cis or trans double bond. Further, the chains may optionally comprise branched hydrocarbon residues. For example, in some embodiments the estolides described herein may comprise at least one compound of Formula II:

-   -   wherein     -   m is an integer equal to or greater than 1;     -   n is an integer equal to or greater than 0;     -   R₁, independently for each occurrence, is an optionally         substituted alkyl that is saturated or unsaturated, and branched         or unbranched     -   R₂ is selected from hydrogen and optionally substituted alkyl         that is saturated or unsaturated, and branched or unbranched;         and     -   R₃ and R₄, independently for each occurrence, are selected from         optionally substituted alkyl that is saturated or unsaturated,         and branched or unbranched,     -   wherein at least one of R₁, R₃, or R₄ comprises an unbranched         undecanyl that is saturated or unsaturated.

In certain embodiments, m is 1. In some embodiments, m is an integer selected from 2, 3, 4, and 5. In some embodiments, n is an integer selected from 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. In some embodiments, one or more R₃ differs from one or more other R₃ in a compound of Formula II. In some embodiments, one or more R₃ differs from R₄ in a compound of Formula II. In some embodiments, if the compounds of Formula II are prepared from one or more polyunsaturated fatty acids, it is possible that one or more of R₃ and R₄ will have one or more sites of unsaturation. Accordingly, in certain embodiments, estolides having multiple sites of unsaturation may be epoxidized and/or sulfurized to provide estolides having multiple sites of epoxidation or sulfurization. In some embodiments, if the compounds of Formula II are prepared from one or more branched fatty acids, it is possible that one or more of R₃ and R₄ will be branched.

In some embodiments, R₃ and R₄ can be CH₃(CH₂)_(y)CH(CH₂)_(x)—, where x is, independently for each occurrence, an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20, and y is, independently for each occurrence, an integer selected from 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, and 20. Where both R₃ and R₄ are CH₃(CH₂)_(y)CH(CH₂)—, the compounds may be compounds according to Formula III.

Without being bound to any particular theory, in certain embodiments, altering the EN produces estolides having desired viscometric properties while substantially retaining or even reducing pour point. For example, in some embodiments the estolides exhibit a decreased pour point upon increasing the EN value. Accordingly, in certain embodiments, a method is provided for retaining or decreasing the pour point of an estolide base oil by increasing the EN of the base oil, or a method is provided for retaining or decreasing the pour point of a composition comprising an estolide base oil by increasing the EN of the base oil. In some embodiments, the method comprises: selecting an estolide base oil having an initial EN and an initial pour point; and removing at least a portion of the base oil, said portion exhibiting an EN that is less than the initial EN of the base oil, wherein the resulting estolide base oil exhibits an EN that is greater than the initial EN of the base oil, and a pour point that is equal to or lower than the initial pour point of the base oil. In some embodiments, the selected estolide base oil is prepared by oligomerizing at least one first unsaturated fatty acid with at least one second unsaturated fatty acid and/or saturated fatty acid. In some embodiments, the removing at least a portion of the base oil is accomplished by distillation, chromatography, membrane separation, phase separation, affinity separation, solvent extraction, or combinations thereof. In some embodiments, the distillation takes place at a temperature and/or pressure that is suitable to separate the estolide base oil into different “cuts” that individually exhibit different EN values. In some embodiments, this may be accomplished by subjecting the base oil temperature of at least about 250° C. and an absolute pressure of no greater than about 25 microns. In some embodiments, the distillation takes place at a temperature range of about 250° C. to about 310° C. and an absolute pressure range of about 10 microns to about 25 microns.

In some embodiments, estolide compounds and compositions exhibit an EN that is greater than or equal to 1, such as an integer or fraction of an integer selected from about 1.0 to about 2.0. In some embodiments, the EN is an integer or fraction of an integer selected from about 1.0 to about 1.6. In some embodiments, the EN is a fraction of an integer selected from about 1.1 to about 1.5. In some embodiments, the EN is selected from a value greater than 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, and 1.9. In some embodiments, the EN is selected from a value less than 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, and 2.0.

In some embodiments, the EN is greater than or equal to 1.5, such as an integer or fraction of an integer selected from about 1.8 to about 2.8. In some embodiments, the EN is an integer or fraction of an integer selected from about 2.0 to about 2.6. In some embodiments, the EN is a fraction of an integer selected from about 2.1 to about 2.5. In some embodiments, the EN is selected from a value greater than 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, and 2.7. In some embodiments, the EN is selected from a value less than 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, and 2.8. In some embodiments, the EN is about 1.8, 2.0, 2.2, 2.4, 2.6, or 2.8.

In some embodiments, the EN is greater than or equal to about 4, such as an integer or fraction of an integer selected from about 4.0 to about 5.0. In some embodiments, the EN is a fraction of an integer selected from about 4.2 to about 4.8. In some embodiments, the EN is a fraction of an integer selected from about 4.3 to about 4.7. In some embodiments, the EN is selected from a value greater than 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, and 4.9. In some embodiments, the EN is selected from a value less than 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9, and 5.0. In some embodiments, the EN is about 4.0, 4.2, 4.4, 4.6, 4.8, or 5.0.

In some embodiments, the EN is greater than or equal to about 5, such as an integer or fraction of an integer selected from about 5.0 to about 6.0. In some embodiments, the EN is a fraction of an integer selected from about 5.2 to about 5.8. In some embodiments, the EN is a fraction of an integer selected from about 5.3 to about 5.7. In some embodiments, the EN is selected from a value greater than 5.0, 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, and 5.9. In some embodiments, the EN is selected from a value less than 5.1, 5.2, 5.3, 5.4, 5.5, 5.6, 5.7, 5.8, 5.9, and 6.0. In some embodiments, the EN is about 5.0, 5.2, 5.4, 5.4, 5.6, 5.8, or 6.0.

In some embodiments, the EN is greater than or equal to 1, such as an integer or fraction of an integer selected from about 1.0 to about 2.0. In some embodiments, the EN is a fraction of an integer selected from about 1.1 to about 1.7. In some embodiments, the EN is a fraction of an integer selected from about 1.1 to about 1.5. In some embodiments, the EN is selected from a value greater than 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, or 1.9. In some embodiments, the EN is selected from a value less than 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, or 2.0. In some embodiments, the EN is about 1.0, 1.2, 1.4, 1.6, 1.8, or 2.0. In some embodiments, the EN is greater than or equal to 1, such as an integer or fraction of an integer selected from about 1.2 to about 2.2. In some embodiments, the EN is an integer or fraction of an integer selected from about 1.4 to about 2.0. In some embodiments, the EN is a fraction of an integer selected from about 1.5 to about 1.9. In some embodiments, the EN is selected from a value greater than 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, and 2.1. In some embodiments, the EN is selected from a value less than 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, and 2.2. In some embodiments, the EN is about 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, or 2.2.

In some embodiments, the EN is greater than or equal to 2, such as an integer or fraction of an integer selected from about 2.8 to about 3.8. In some embodiments, the EN is an integer or fraction of an integer selected from about 2.9 to about 3.5. In some embodiments, the EN is an integer or fraction of an integer selected from about 3.0 to about 3.4. In some embodiments, the EN is selected from a value greater than 2.0, 2.1, 2.2, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.4, 3.5, 3.6, and 3.7. In some embodiments, the EN is selected from a value less than 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, and 3.8. In some embodiments, the EN is about 2.0, 2.2, 2.4, 2.6, 2.8, 3.0, 3.2, 3.4, 3.6, or 3.8. Typically, base stocks and lubricant compositions exhibit certain lubricity, viscosity, and/or pour point characteristics. For example, in certain embodiments, suitable viscosity characteristics of the base oil may range from about 10 cSt to about 250 cSt at 40° C., and/or about 3 cSt to about 30 cSt at 100° C. In some embodiments, the compounds and compositions may exhibit viscosities within a range from about 50 cSt to about 150 cSt at 40° C., and/or about 10 cSt to about 20 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities less than about 55 cSt at 40° C. or less than about 45 cSt at 40° C., and/or less than about 12 cSt at 100° C. or less than about 10 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 25 cSt to about 55 cSt at 40° C., and/or about 5 cSt to about 11 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 35 cSt to about 45 cSt at 40° C., and/or about 6 cSt to about 10 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 38 cSt to about 43 cSt at 40° C., and/or about 7 cSt to about 9 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities less than about 120 cSt at 40° C. or less than about 100 cSt at 40° C., and/or less than about 18 cSt at 100° C. or less than about 17 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit a viscosity within a range from about 70 cSt to about 120 cSt at 40° C., and/or about 12 cSt to about 18 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 80 cSt to about 100 cSt at 40° C., and/or about 13 cSt to about 17 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 85 cSt to about 95 cSt at 40° C., and/or about 14 cSt to about 16 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities greater than about 180 cSt at 40° C. or greater than about 200 cSt at 40° C., and/or greater than about 20 cSt at 100° C. or greater than about 25 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit a viscosity within a range from about 180 cSt to about 230 cSt at 40° C., and/or about 25 cSt to about 31 cSt at 100° C. In some embodiments, estolide compounds and compositions may exhibit viscosities within a range from about 200 cSt to about 250 cSt at 40° C., and/or about 25 cSt to about 35 cSt at 100° C. In some embodiments, estolide compounds and compositions may exhibit viscosities within a range from about 210 cSt to about 230 cSt at 40° C., and/or about 28 cSt to about 33 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 200 cSt to about 220 cSt at 40° C., and/or about 26 cSt to about 30 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 205 cSt to about 215 cSt at 40° C., and/or about 27 cSt to about 29 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities less than about 45 cSt at 40° C. or less than about 38 cSt at 40° C., and/or less than about 10 cSt at 100° C. or less than about 9 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit a viscosity within a range from about 20 cSt to about 45 cSt at 40° C., and/or about 4 cSt to about 10 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 28 cSt to about 38 cSt at 40° C., and/or about 5 cSt to about 9 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 30 cSt to about 35 cSt at 40° C., and/or about 6 cSt to about 8 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities less than about 80 cSt at 40° C. or less than about 70 cSt at 40° C., and/or less than about 14 cSt at 100° C. or less than about 13 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit a viscosity within a range from about 50 cSt to about 80 cSt at 40° C., and/or about 8 cSt to about 14 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 60 cSt to about 70 cSt at 40° C., and/or about 9 cSt to about 13 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 63 cSt to about 68 cSt at 40° C., and/or about 10 cSt to about 12 cSt at 100° C.

In some embodiments, the estolide compounds and compositions may exhibit viscosities greater than about 120 cSt at 40° C. or greater than about 130 cSt at 40° C., and/or greater than about 15 cSt at 100° C. or greater than about 18 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit a viscosity within a range from about 120 cSt to about 150 cSt at 40° C., and/or about 16 cSt to about 24 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 130 cSt to about 160 cSt at 40° C., and/or about 17 cSt to about 28 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 130 cSt to about 145 cSt at 40° C., and/or about 17 cSt to about 23 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities within a range from about 135 cSt to about 140 cSt at 40° C., and/or about 19 cSt to about 21 cSt at 100° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 300, 350, or 400 cSt. at 40° C. In some embodiments, the estolide compounds and compositions may exhibit viscosities of about 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, and 30 cSt at 100° C. In certain embodiments, estolides may exhibit desirable low-temperature pour point properties. In some embodiments, the estolide compounds and compositions may exhibit a pour point lower than about −25° C., about −35° C., −40° C., or even about −50° C. In some embodiments, the estolide compounds and compositions have a pour point of about −25° C. to about −45° C. In some embodiments, the pour point falls within a range of about −30° C. to about −40° C., about −34° C. to about −38° C., about −30° C. to about −45° C., −35° C. to about −45° C., 34° C. to about −42° C., about −38° C. to about −42° C., or about 36° C. to about −40° C. In some embodiments, the pour point falls within the range of about −27° C. to about −37° C., or about −30° C. to about −34° C. In some embodiments, the pour point falls within the range of about −25° C. to about −35° C., or about −28° C. to about −32° C. In some embodiments, the pour point falls within the range of about −28° C. to about −38° C., or about −31° C. to about −35° C. In some embodiments, the pour point falls within the range of about −31° C. to about −41° C., or about −34° C. to about −38° C. In some embodiments, the pour point falls within the range of about −40° C. to about −50° C., or about −42° C. to about −48° C. In some embodiments, the pour point falls within the range of about −50° C. to about −60° C., or about −52° C. to about −58° C. In some embodiments, the upper bound of the pour point is less than about −35° C., about −36° C., about −37° C., about −38° C., about −39° C., about −40° C., about −41° C., about −42° C., about −43° C., about −44° C., or about −45° C. In some embodiments, the lower bound of the pour point is greater than about −70° C., about −69° C., about −68° C., about −67° C., about −66° C., about −65° C., about −64° C., about −63° C., about −62° C., about −61° C., about −60° C., about −59° C., about −58° C., about −57° C., about −56° C., −55° C., about −54° C., about −53° C., about −52° C., −51, about −50° C., about −49° C., about −48° C., about −47° C., about −46° C., or about −45° C.

In addition, in certain embodiments, the estolides may exhibit decreased Iodine Values (IV) when compared to estolides prepared by other methods. IV is a measure of the degree of total unsaturation of an oil, and is determined by measuring the amount of iodine per gram of estolide (cg/g). In certain instances, oils having a higher degree of unsaturation may be more susceptible to creating corrosiveness and deposits, and may exhibit lower levels of oxidative stability. Compounds having a higher degree of unsaturation will have more points of unsaturation for iodine to react with, resulting in a higher IV. Thus, in certain embodiments, it may be desirable to reduce the IV of estolides in an effort to increase the oil's oxidative stability, while also decreasing harmful deposits and the corrosiveness of the oil.

In some embodiments, estolide compounds and compositions described herein have an IV of less than about 40 cg/g or less than about 35 cg/g. In some embodiments, estolides have an IV of less than about 30 cg/g, less than about 25 cg/g, less than about 20 cg/g, less than about 15 cg/g, less than about 10 cg/g, or less than about 5 cg/g. The IV of a composition may be reduced by decreasing the estolide's degree of unsaturation. This may be accomplished by, for example, by increasing the amount of saturated capping materials relative to unsaturated capping materials when synthesizing the estolides. Alternatively, in certain embodiments, IV may be reduced by hydrogenating estolides having unsaturated caps.

In certain embodiments, the estolides described herein may be suitable for use as anti-wear and/or extreme pressure agents. In certain embodiments, the anti-wear and/or extreme pressure agent comprises at least one sulfurized estolide. In certain embodiments, the at least one sulfurized estolide is a component of a lubricating composition, such as a grease or a motor oil. In certain embodiments, the lubricating composition further comprises at least one base oil, such as a petroleum-derived base oil. In certain embodiments, the base oil comprises at least one estolide that is not sulfurized. In certain embodiments, the lubricating composition further comprises at least one additive. In certain embodiments, the at least one additive comprises one or more compounds selected from separation preventers, stability enhancers, biocides, surfactants, corrosion inhibitors, antioxidants, abrasion inhibitors, viscosity index improvers, pour-point depressants, detergent-dispersants, and antifoaming agents.

In certain embodiments, sulfurized estolides may be prepared by sulfurizing one or more estolide compounds having at least one site of unsaturation. In certain embodiments, the sulfurizing may be accomplished by any method known to those of ordinary skill in the art, such as direct sulfurization utilizing elemental sulfur. Other exemplary sulfurizing methods include, but are not limited to, those utilizing one or more compounds selected from sulfur monochloride, sulfur dichloride, sodium sulfide/H₂S/sulfur, sodium sulfide/H₂S, sodium sulfide/sodium mercaptide/sulfur, and sulfurization utilizing a chain transfer agent.

In certain embodiments, the lubricating composition comprises at least one sulfurized estolide and at least one base oil. In certain embodiments, the mass ratio of the at least one sulfurized estolide to the at least one base oil is about 99:1 to about 1:99. In certain embodiments, the mass ratio of the at least one sulfurized estolide compound to the at least one base oil is about 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, 35:65, 30:70, 25:75, 20:80, 15:85, 10:90, or 5:95. In certain embodiments, the lubricating composition comprises from about 0 wt. % to about 95 wt. %, such as about 1 wt. % to about 80 wt. %, about 1 wt. % to about 70 wt. % or about 1 wt. % to about 50 wt. % of the at least one sulfurized estolide compound. In certain embodiments, the at least one sulfurized estolide compound is present in amounts of about 0 to about 30 wt. % of the lubricating composition. In certain embodiments, the at least one sulfurized estolide compound is present in amounts of about 0 to about 20, about 0 to about 15, about 0 to about 10, about 0 to about 8, about 0 to about 6, about 0 to about 4, or about 0 to about 2 wt. % of the lubricating composition. In certain embodiments, the at least one sulfurized estolide compound is present in amounts of about 0 to about 5 wt. % of the lubricating composition, such as about 0.1 to about 3 wt % or 0.01 to about 1 wt. %. In certain embodiments, the at least one sulfurized estolide compound is present in amounts of about 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, 2.6, 2.8, or 3.0 wt. % of the lubricating composition. In certain embodiments, the at least one sulfurized estolide compound is present in amounts of about 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, or 0.1 wt. % of the lubricating composition.

In certain embodiments are described compositions comprising at least one epoxidized estolide compound. In certain embodiments, the composition is a plasticized composition. In certain embodiments, the plasticized composition further comprises at least one polymeric material. In certain embodiments, the plasticized composition may comprise a solid, semi-solid, or liquid composition. In certain embodiments, the plasticized composition may be referred to as a plastisol. In certain embodiments, the plastisol comprises a polymeric material (e.g., non-crosslinked organic polymer) and a liquid phase (e.g., epoxidized estolide and/or a diluent).

In certain embodiments, epoxidized estolides can be prepared by epoxidizing one or more estolide compounds having at least one site of unsaturation. In certain embodiments, the epoxidizing may be accomplished using any of the methods generally known to those of ordinary skill in the art, such as using hydrogen peroxide and/or formic acid, or those methods involving one or more percarboxylic acids such as m-chloroperbenzoic acid, peracetic acid, or performic acid. Exemplary epoxidation methods also include those set forth in D. Swern, Organic Peroxides, Volume 2, 355-533, Interscience Publishers, 1971, which is incorporated by reference in its entirety for all purposes.

As used herein, the term “polymeric material” means any synthetic or naturally-occurring polymeric material, including copolymers and homopolymers. In certain embodiments, the at least one polymeric material comprises one or more compounds selected from polyvinyl polymers, polyolefins, acrylate polymers, methacrylate polymers, styrene polymers, polyesters, polyamides, polycarbonates, polyurethanes, polysulfides, silicones, elastomers, and rubbers. In certain embodiments, the mass ratio of the at least one epoxidized estolide compound to the at least one polymeric material is about 99:1 to about 1:99. In certain embodiments, the mass ratio of the at least one epoxidized estolide compound to the at least one polymeric material is about 95:5, 90:10, 85:15, 80:20, 75:25, 70:30, 65:35, 60:40, 55:45, 50:50, 45:55, 40:60, 35:65, 30:70, 25:75, 20:80, 15:85, 10:90, or 5:95. In certain embodiments, the plasticized composition comprises from about 0 wt. % to about 95 wt. %, such as about 1 wt. % to about 80 wt. %, about 1 wt. % to about 70 wt. % or about 1 wt. % to about 50 wt. % of the at least one polymeric material. In certain embodiments, the at least one polymeric material is present in amounts of about 1 wt. % to about 30 wt. %, about 1 wt. % to about 25 wt. %, or about 0.1 wt. % to about 20 wt. % of the plasticized composition. In certain embodiments, the at least one polymeric material comprises about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, or 80 wt. % of the plasticized composition.

As used herein, polymeric materials may comprise homopolymers or copolymers. Accordingly, unless indicated otherwise, it should be understood that reference to a polymer such as polyethylene includes, but is not limited to, a polyethylene homopolymer and a copolymer comprising ethylene monomers and at least one non-ethylene monomer (e.g., vinyl acetate). Exemplary polymeric materials include, but are not limited to, polyvinyl chlorides (PVC), polyethylenes, polypropylenes, polybutylenes, poly(ester amide), polystyrene-polyisobutylene-polystyrene block copolymer (SIS), polystyrene, polyisobutylene, polycaprolactone (PCL), poly(L-lactide), poly(D,L-lactide), polylactic acid (PLA), poly(lactide-co-glycolide), poly(glycolide), polyalkylene, polyfluoroalkylene, polyhydroxyalkanoate, poly(3-hydroxybutyrate), poly(4-hydroxybutyrate), poly(3-hydroxyvalerate), poly(3-hydroxybutyrate-co-3-hydroxyvalerate), poly(3-hydroxyhexanoate), poly(4-hydroxyhexanoate), mid-chain polyhydroxyalkanoate, poly(trimethylene carbonate), poly(orthoester), polyphosphazenes, poly(phosphoester), poly(tyrosine derived arylates), poly(tyrosine derived carbonates), polydimethyloxanone (PDMS), polyvinylidene fluoride (PVDF), polyhexafluoropropylene (HFP), polydimethylsiloxane, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE), poly(butyl methacrylate), poly(methyl methacrylate), poly(methacrylates), poly(vinyl acetate), poly(ethylene-co-vinyl acetate), poly(ethylene-co-vinyl alcohol), poly(ester urethanes), poly(ether-urethanes), poly(carbonate-urethanes), poly(silicone-urethanes), poly(2-hydroxyethyl methacrylate), Solef™ PVDF (polyvinylidene fluoride), poly(urea-urethanes), hydroxylethyl methacrylate (HEMA), hydroxypropyl methacrylate (HPMA), hydroxypropylmethacrylamide, alkoxymethacrylate, alkoxyacrylate, 3-trimethylsilylpropyl methacrylate (TMSPMA), poly(methyl methacrylate) (PMMA), poly(ethylene glycol) (PEG), polypropylene glycol) (PPG), PEG acrylate (PEGA), PEG methacrylate, methacrylic acid (MA), ethylene-vinyl acetate, acrylic acid (AA), SIS-PEG, polystyrene-PEG, polyisobutylene-PEG, PCL-PEG, PLA-PEG, PMMA-PEG, PDMS-PEG, PVDF-PEG, poly(tetramethylene glycol), polyhydroxyalkanoates (PHAs), poly(ester amides), polycaprolactones, poly(L-lactide), poly(D,L-lactide), poly(D,L-lactide-co-PEG) block copolymers, poly(D,L-lactide-co-trimethylene carbonate), polyglycolides, poly(lactide-co-glycolide), polydioxanones, polyorthoesters, polyanhydrides, poly(glycolic acid-co-trimethylene carbonate), polyphosphoesters, polyphosphoester urethanes, poly(amino acids), polycyanoacrylates, poly(trimethylene carbonate), poly(imino carbonate), polycarbonates, polyurethanes, copoly(ether-esters) (e.g., PEO/PLA), polyalkylene oxalates, polyphosphazenes, PHA-PEG, poly(alpha-hydroxyacids), poly(beta-hydroxyacids) such as poly(3-hydroxybutyrate) (PHB), poly(3-hydroxybutyrate-co-valerate) (PHBV), poly(3-hydroxypropionate) (PHP), poly(3-hydroxyhexanoate) (PHH), a poly(4-hydroxyacid) such as poly(4-hydroxybutyrate), poly(4-hydroxyvalerate), or poly(4-hydroxyhexanoate), poly(hydroxyvalerate), polyanhydrides, poly(hydroxyethyl methacylate), poly(N-acylhydroxyproline)esters, poly(N-palmitoyl hydroxyproline)esters, polyphosphazenes, poly(tyrosine carbonates), and poly(tyrosine arylates).

In certain embodiments, the at least one polymeric material is biodegradable. In certain embodiments, the biodegradable polymeric material comprises one or more materials selected from biodegradable polyesters and biodegradable polyethylenes. Exemplary biodegradable polyesters include, but are not limited to, polyglycolic acid, polylactic acid, polycaprolactone, polyhydroxybutyrate, polyhydroxyvalerate, and polyhydroxyvaleric acid. Exemplary biodegradable polyethylenes include, but are not limited to, polyvinylacetate, poly(butylenes succinate), polyvinyl alcohol, and poly-p-dioxanone.

Exemplary elastomers and rubbers include, but are not limited to, natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), 1,2-butadiene rubber, styrene-butadiene rubber (SBR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (BR), ethylene-propylene-diene rubber (EPDM) and other diene rubbers and their hydrogenated products, ethylene-propylene rubber (EPM), ethylene-acrylic rubber (AEM), ethylene-butene rubber (EBM), chlorosulfonated polyethylene, acrylic rubber, fluororubber, polyethylene rubber, polypropylene rubber, and other olefin rubbers, epichlorohydrin rubbers, polysulfide rubbers, silicone rubbers, and urethane rubbers. In certain embodiments, the elastomer may comprise a resin component. Exemplary elastomers may include optionally hydrogenated polystyrene elastomeric polymers (e.g., styrene-butadiene-styrene (SBS), styrene-isoprene-styrene (SIS), and styrene-ethylene/butylene-styrene (SEBS)), polyolefin elastomeric polymers, polyvinyl chloride elastomeric polymers, polyurethane elastomeric polymers, polyester elastomeric polymers, and polyamide elastomeric polymers.

In certain embodiments, the plasticized composition further comprises at least one thermal stabilizer. In certain embodiments, the at least one thermal stabilizer comprises one or more compounds selected from epoxy compounds, metallic stabilizers, phosphites, nitrogen-containing stabilizers, polyols, hydrotalcites, zeolites, and dawsonites.

Exemplary epoxy thermal stabilizers include, but are not limited to, epoxidized oils such as soybean oil, lard oil, olive oil, linseed oil, peanut oil, castor oil, corn oil, tung oil, and cottonseed oil. Other exemplary epoxy thermal stabilizers may include, but are not limited to, epichlorhydrin/bis-phenol A resins, butoxypropylene oxide, glycidyl epoxystearate, epoxidized alpha-olefins, epoxidized glycidyl soyate, epoxidized butyl toluate, glycidol, vinyl cyclo-hexene dioxide, glycidyl ethers of resorcinol, hydroquinone, 1,5-dihydroxynaphthalene-, glycerine, pentaerythritol, and sorbitol, allyl glycidyl ether, butyl glycidyl ether, cyclohexane oxide, 4-(2,3-epoxyproproxy)acetophenone, mesityl oxide epoxide, and 2-ethyl-3-propyl glycidamine.

Exemplary phosphite thermal stabilizers include, but are not limited to, trialkylphosphites such as trioctyl phosphite, tridecyl phosphite, tridodecyl phosphite, tri(tetradecyl) phosphite, tricyclohexyl phosphite, tristearyl phosphite, distearyl-pentaerythritol diphosphite, and trioleyl phosphite; triaryl phosphites such as triphenyl phosphite, tricresyl phosphite, and tris-p-nonylphenyl phosphite, alkyldiaryl phosphites such as phenyldidecyl phosphite and (2,4-di-tert-butylphenyl)didodecyl phosphite, dialkylaryl phosphites, and thiophosphites such as trithiohexyl phosphite, trithiooctyl phosphite, trithiolauryl phosphite, and trithiobenzyl phosphite.

Exemplary metallic thermal stabilizers include, but are not limited to, metal salts and organometallic salts, such as oxides, hydroxides, sulfides, sulfates, halides, phosphates, phenates, perchlorates, carboxylates, and carbonates of metals like zinc, barium, strontium, calcium, tin, magnesium, cobalt, nickel, titanium, antimony, and aluminum, such as calcium hydroxide, magnesium hydroxide, calcium stearate, calcium 2-ethylhexanoate, calcium octanoate, calcium recinoaleate, calcium myristate, calcium palmitate, barium laurate, barium di(nonylphenolate), barium stearate, aluminum stearate, and hydrotalcite. Exemplary organometallic thermal stabilizers also include, but are not limited to, organotin carboxylates and mercaptides, such as butyltin tris dodecyl mercaptide, dibutylin dilaurate, dibutyltin didodecyl mercaptide, dianhydride tris dibutylstannane diol, dihydrocarbontin salts of carboxy mercaptals, monosulfides and/or polysulfides of the organotin mercaptides of mercaptoalkyl carboxylates and/or alkyl thioglycolates.

Exemplary nitrogen-containing thermal stabilizers include, but are not limited to, dicyandiamide, hindered amines, melamine, urea, dimethyl hydantoin, guanidine, thiourea, 2-phenylindoles, aminocrontonates, N-alkyl and N-phenyl substituted maleimides, 1,3-dialkyl-6-amino-uracil derivatives, pyrrolodiazine diones, and monomeric, oligomeric, and polymeric 2,2,6,6-tetramethylpiperidine compounds. Other exemplary nonmetallic stabilizers include, but are not limited to, dilaurylthiodipropionate, distearyl 3,3′-thiopropionate, dibenzyl-3,3′-thiodipropionate, dicyclohexyl-3,3′-thiodipropionate, dioleyl-3,3′-thiodipropionate, didecyl-3,3′-thiodipropionate, diethyl-3,3′-thiodipropionate, lauryl ester of 3-mercaptopropionic acid, lauryl ester of 3-lauryl mercaptopropionic acid, and the phenyl ester of 3-octyl mercaptopropionic acid.

In addition to the at least one epoxidized estolide compound, the plasticized compositions described herein may further comprise one or more plasticizers selected from petroleum-derived phthalates and benzoate compounds, such as dioctyl phthalate (DOP) and diallyl phthalate (DAP). Other exemplary plasticizers include, but are not limited to, one or more of the exemplary epoxy compound previously described herein. In certain embodiments, non-epoxidized estolide compounds, such as those used to prepare the epoxidized estolides described herein, may also be used as plasticizers. Accordingly, in certain embodiments, the plasticized composition comprises at least one polymeric material and co-blend of at least one epoxidized estolide and at least one non-epoxidized estolide.

In certain embodiments, the plasticized composition further comprises at least one additive comprising one or more compounds selected from diluents, pigments, colorants, UV absorbers, fillers, and flame retarding agents. Exemplary diluents include, but are not limited to, hydrocarbons and ketones that are liquids at 25° C. Exemplary hydrocarbons include aromatic, aliphatic, and/or cycloaliphatic hydrocarbons.

In certain embodiments, the plasticized composition may be useful as a film, coating, ink, or paint composition. In certain embodiments, the plasticized composition comprises a coating that may be applied onto metallic or non-metallic surfaces by dipping, spraying, or the use of coating rollers. In certain embodiments, the plasticized composition comprises a coating to be applied to fabrics, such as those used in the construction of resilient floor and wall coverings.

In certain embodiments, the plasticized composition comprises a solid, semi-solid, and/or molded material. In certain embodiments, the plasticized composition comprises an article of manufacture. In certain embodiments, the article of manufacture comprises one or more items selected from cookware, storage ware, furniture, appliances, automotive components, boat components, toys, sportswear, medical devices, medical implants, containers, tubes, pipes, sporting equipment, electronics, wire jacketing, cable jacketing, crates, containers, packaging, labware, floor mats, instrumentation, liquid storage containers, bags, pouches, bottles, adhesives, shoe soles, gaskets, elastic fibers, and sealants. In certain embodiments the article is manufactured by any method known to those of skill in the art. In certain embodiments, the method of manufacture is selected from injection molding, compression molding, transfer molding, casting, extruding, thermoforming, blow molding, and rotational molding.

The present disclosure further relates to methods of making estolides that can be sulfurized and/or epoxidized to provide compounds according to Formula I, II, and III. By way of example, the reaction of an unsaturated fatty acid with an organic acid and the esterification of the resulting free acid estolide are illustrated and discussed in the following Schemes 1 and 2. The particular structural formulas used to illustrate the reactions correspond to those for synthesis of compounds that can be subsequently sulfurized and/or epoxidized to provide compounds according to Formula I and III; however, the methods apply equally to the synthesis of compounds according to Formula II, with use of compounds having structure corresponding to R₃ and R₄ with a reactive site of unsaturation.

As illustrated below, compound 100 represents an unsaturated fatty acid that may serve as the basis for preparing the estolide compounds described herein.

In Scheme 1, wherein x is, independently for each occurrence, an integer selected from 0 to 20, y is, independently for each occurrence, an integer selected from 0 to 20, n is an integer greater than or equal to 1, and R₁ is an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, unsaturated fatty acid 100 may be combined with compound 102 and a proton from a proton source to form free acid estolide 104. In certain embodiments, compound 102 is not included, and unsaturated fatty acid 100 may be exposed alone to acidic conditions to form free acid estolide 104, wherein R₁ would represent an unsaturated alkyl group. In certain embodiments, if compound 102 is included in the reaction, R₁ may represent one or more optionally substituted alkyl residues that are saturated or unsaturated and branched or unbranched. Any suitable proton source may be implemented to catalyze the formation of free acid estolide 104, including but not limited to homogenous acids and/or strong acids like hydrochloric acid, sulfuric acid, perchloric acid, nitric acid, triflic acid, and the like.

Similarly, in Scheme 2, wherein x is, independently for each occurrence, an integer selected from 0 to 20, y is, independently for each occurrence, an integer selected from 0 to 20, n is an integer greater than or equal to 1, and R₁ and R₂ are each an optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, free acid estolide 104 may be esterified by any suitable procedure known to those of skilled in the art, such as acid-catalyzed reduction with alcohol 202, to yield esterified estolide 204. Other exemplary methods may include other types of Fischer esterification, such as those using Lewis acid catalysts such as BF₃.

As discussed above, in certain embodiments, the estolides described herein may have improved properties which render them useful in lubricating compositions. Such applications may include, without limitation, crankcase oils, gearbox oils, hydraulic fluids, drilling fluids, two-cycle engine oils, greases, and the like. Other suitable uses may include marine applications, where biodegradability and toxicity are of concern. In certain embodiments, the nontoxic nature of certain estolides described herein may also make them suitable for use as lubricants in the cosmetic and food industries.

In some embodiments, it may be desirable to prepare lubricant compositions comprising one or more of the estolides described herein. For example, in certain embodiments, the estolides described herein may be blended with one or more additives selected from polyalphaolefins, synthetic esters, polyalkylene glycols, mineral oils (Groups I, II, and III), pour point depressants, viscosity modifiers, anti-corrosives, antiwear agents, detergents, dispersants, colorants, antifoaming agents, and demulsifiers. In addition, or in the alternative, in certain embodiments, the estolides described herein may be co-blended with one or more synthetic or petroleum-based oils to achieve desired viscosity and/or pour point profiles. In certain embodiments, certain estolides described herein also mix well with gasoline, so that they may be useful as fuel components or additives.

In all of the foregoing examples, the compounds described may be useful alone, as mixtures, or in combination with other compounds, compositions, and/or materials.

Methods for obtaining the novel compounds described herein will be apparent to those of ordinary skill in the art, suitable procedures being described, for example, in the examples below, and in the references cited herein.

EXAMPLES

Analytics

Nuclear Magnetic Resonance:

NMR spectra were collected using a Bruker Avance 500 spectrometer with an absolute frequency of 500.113 MHz at 300 K using CDCl₃ as the solvent. Chemical shifts were reported as parts per million from tetramethylsilane. The formation of a secondary ester link between fatty acids, indicating the formation of estolide, was verified with ¹H NMR by a peak at about 4.84 ppm.

Estolide Number (EN):

The EN was measured by GC analysis. It should be understood that the EN of a composition specifically refers to EN characteristics of any estolide compounds present in the composition. Accordingly, an estolide composition having a particular EN may also comprise other components, such as natural or synthetic additives, other non-estolide base oils, fatty acid esters, e.g., triglycerides, and/or fatty acids, but the EN as used herein, unless otherwise indicated, refers to the value for the estolide fraction of the estolide composition.

Iodine Value (IV):

The iodine value is a measure of the degree of total unsaturation of an oil. IV is expressed in terms of centigrams of iodine absorbed per gram of oil sample. Therefore, the higher the iodine value of an oil the higher the level of unsaturation is of that oil. The IV may be measured and/or estimated by GC analysis. Where a composition includes unsaturated compounds other than estolides as set forth in Formula I, II, and III, the estolides can be separated from other unsaturated compounds present in the composition prior to measuring the iodine value of the constituent estolides. For example, if a composition includes unsaturated fatty acids or triglycerides comprising unsaturated fatty acids, these can be separated from the estolides present in the composition prior to measuring the iodine value for the one or more estolides.

Acid Value:

The acid value is a measure of the total acid present in an oil. Acid value may be determined by any suitable titration method known to those of ordinary skill in the art. For example, acid values may be determined by the amount of KOH that is required to neutralize a given sample of oil, and thus may be expressed in terms of mg KOH/g of oil.

Gas Chromatography (GC):

GC analysis was performed to evaluate the estolide number (EN) and iodine value (IV) of the estolides. This analysis was performed using an Agilent 6890N series gas chromatograph equipped with a flame-ionization detector and an autosampler/injector along with an SP-2380 30 m×0.25 mm i.d. column.

The parameters of the analysis were as follows: column flow at 1.0 mL/min with a helium head pressure of 14.99 psi; split ratio of 50:1; programmed ramp of 120-135° C. at 20° C./min, 135-265° C. at 7° C./min, hold for 5 min at 265° C.; injector and detector temperatures set at 250° C.

Measuring EN and IV by GC:

To perform these analyses, the fatty acid components of an estolide sample were reacted with MeOH to form fatty acid methyl esters by a method that left behind a hydroxy group at sites where estolide links were once present. Standards of fatty acid methyl esters were first analyzed to establish elution times.

Sample Preparation:

To prepare the samples, 10 mg of estolide was combined with 0.5 mL of 0.5M KOH/MeOH in a vial and heated at 100° C. for 1 hour. This was followed by the addition of 1.5 mL of 1.0 M H₂SO₄/MeOH and heated at 100° C. for 15 minutes and then allowed to cool to room temperature. One (1) mL of H₂O and 1 mL of hexane were then added to the vial and the resulting liquid phases were mixed thoroughly. The layers were then allowed to phase separate for 1 minute. The bottom H₂O layer was removed and discarded. A small amount of drying agent (Na₂SO₄ anhydrous) was then added to the organic layer after which the organic layer was then transferred to a 2 mL crimp cap vial and analyzed.

EN Calculation:

The EN is measured as the percent hydroxy fatty acids divided by the percent non-hydroxy fatty acids. As an example, a dimer estolide would result in half of the fatty acids containing a hydroxy functional group, with the other half lacking a hydroxyl functional group. Therefore, the EN would be 50% hydroxy fatty acids divided by 50% non-hydroxy fatty acids, resulting in an EN value of 1 that corresponds to the single estolide link between the capping fatty acid and base fatty acid of the dimer.

IV Calculation:

The iodine value is estimated by the following equation based on ASTM Method D97 (ASTM International, Conshohocken, Pa.):

${I\; V} = {\sum\;{100 \times \frac{A_{f} \times M\; W_{I} \times d\; b}{M\; W_{f}}}}$

-   -   A_(f)=fraction of fatty compound in the sample     -   MW_(I)=253.81, atomic weight of two iodine atoms added to a         double bond     -   db=number of double bonds on the fatty compound     -   MW_(f)=molecular weight of the fatty compound

The properties of exemplary estolide compounds and compositions described herein are identified in the following examples and tables.

Other Measurements:

Except as otherwise described, pour point is measured by ASTM Method D97-96a, cloud point is measured by ASTM Method D2500, viscosity/kinematic viscosity is measured by ASTM Method D445-97, viscosity index is measured by ASTM Method D2270-93 (Reapproved 1998), specific gravity is measured by ASTM Method D4052, flash point is measured by ASTM Method D92, evaporative loss is measured by ASTM Method D5800, vapor pressure is measured by ASTM Method D5191, and acute aqueous toxicity is measured by Organization of Economic Cooperation and Development (OECD) 203.

Example 1

The acid catalyst reaction was conducted in a 50 gallon Pfaudler RT-Series glass-lined reactor. Oleic acid (65 Kg, OL 700, Twin Rivers) was added to the reactor with 70% perchloric acid (992.3 mL, Aldrich Cat#244252) and heated to 60° C. in vacuo (10 torr abs) for 24 hrs while continuously being agitated. After 24 hours the vacuum was released. 2-Ethylhexanol (29.97 Kg) was then added to the reactor and the vacuum was restored. The reaction was allowed to continue under the same conditions (60° C., 10 torr abs) for 4 more hours. At which time, KOH (645.58 g) was dissolved in 90% ethanol/water (5000 mL, 90% EtOH by volume) and added to the reactor to quench the acid. The solution was then allowed to cool for approximately 30 minutes. The contents of the reactor were then pumped through a 1 micron (μ) filter into an accumulator to filter out the salts. Water was then added to the accumulator to wash the oil. The two liquid phases were thoroughly mixed together for approximately 1 hour. The solution was then allowed to phase separate for approximately 30 minutes. The water layer was drained and disposed of. The organic layer was again pumped through a 1μ filter back into the reactor. The reactor was heated to 60° C. in vacuo (10 torr abs) until all ethanol and water ceased to distill from solution. The reactor was then heated to 100° C. in vacuo (10 torr abs) and that temperature was maintained until the 2-ethylhexanol ceased to distill from solution. The remaining material was then distilled using a Myers 15 Centrifugal Distillation still at 200° C. under an absolute pressure of approximately 12 microns (0.012 torr) to remove all monoester material leaving behind estolides (Ex. 1). Certain data are reported below in Tables 1 and 8.

Example 2

The acid catalyst reaction was conducted in a 50 gallon Pfaudler RT-Series glass-lined reactor. Oleic acid (50 Kg, OL 700, Twin Rivers) and whole cut coconut fatty acid (18.754 Kg, TRC 110, Twin Rivers) were added to the reactor with 70% perchloric acid (1145 mL, Aldrich Cat#244252) and heated to 60° C. in vacuo (10 torr abs) for 24 hrs while continuously being agitated. After 24 hours the vacuum was released. 2-Ethylhexanol (34.58 Kg) was then added to the reactor and the vacuum was restored. The reaction was allowed to continue under the same conditions (60° C., 10 torr abs) for 4 more hours. At which time, KOH (744.9 g) was dissolved in 90% ethanol/water (5000 mL, 90% EtOH by volume) and added to the reactor to quench the acid. The solution was then allowed to cool for approximately 30 minutes. The contents of the reactor were then pumped through a 1μ filter into an accumulator to filter out the salts. Water was then added to the accumulator to wash the oil. The two liquid phases were thoroughly mixed together for approximately 1 hour. The solution was then allowed to phase separate for approximately 30 minutes. The water layer was drained and disposed of. The organic layer was again pumped through a 1μ filter back into the reactor. The reactor was heated to 60° C. in vacuo (10 torr abs) until all ethanol and water ceased to distill from solution. The reactor was then heated to 100° C. in vacuo (10 ton abs) and that temperature was maintained until the 2-ethylhexanol ceased to distill from solution. The remaining material was then distilled using a Myers 15 Centrifugal Distillation still at 200° C. under an absolute pressure of approximately 12 microns (0.012 torr) to remove all monoester material leaving behind estolides (Ex. 2). Certain data are reported below in Tables 2 and 7.

Example 3

The estolides produced in Example 1 (Ex. 1) were subjected to distillation conditions in a Myers 15 Centrifugal Distillation still at 300° C. under an absolute pressure of approximately 12 microns (0.012 torr). This resulted in a primary distillate having a lower EN average (Ex. 3A), and a distillation residue having a higher EN average (Ex. 3B). Certain data are reported below in Tables 1 and 8.

TABLE 1 Pour Iodine Estolide Point Value Base Stock EN (° C.) (cg/g) Ex. 3A 1.35 −32 31.5 Ex. 1 2.34 −40 22.4 Ex. 3B 4.43 −40 13.8

Example 4

Estolides produced in Example 2 (Ex. 2) were subjected to distillation conditions in a Myers 15 Centrifugal Distillation still at 300° C. under an absolute pressure of approximately 12 microns (0.012 torr). This resulted in a primary distillate having a lower EN average (Ex. 4A), and a distillation residue having a higher EN average (Ex. 4B). Certain data are reported below in Tables 2 and 7.

TABLE 2 Estolide Iodine Base Stock EN Pour Point (° C.) Value (cg/g) Ex. 4A 1.31 −30 13.8 Ex. 2 1.82 −33 13.2 Ex. 4B 3.22 −36 9.0

Example 5

Estolides produced by the method set forth in Example 1 were subjected to distillation conditions (ASTM D-6352) at 1 atm over the temperature range of about 0° C. to about 710° C., resulting in 10 different estolide cuts recovered at increasing temperatures The amount of material distilled from the sample in each cut and the temperature at which each cut distilled (and recovered) are reported below in Table 3:

TABLE 3 Cut (% of total) Temp. (° C.) 1 (1%) 416.4 2 (1%) 418.1 3 (3%) 420.7  4 (20%) 536.4  5 (25%) 553.6  6 (25%) 618.6  7 (20%) 665.7 8 (3%) 687.6 9 (1%) 700.6 10 (1%)  709.1

Example 6

Estolides made according to the method of Example 2 were subjected to distillation conditions (ASTM D-6352) at 1 atm over the temperature range of about 0° C. to about 730° C., which resulted in 10 different estolide cuts. The amount of each cut and the temperature at which each cut was recovered are reported in Table 4.

TABLE 4 Cut (% of total) Temp. (° C.) 1 (1%) 417.7 2 (1%) 420.2 3 (3%) 472.0 4 (5%) 509.7  5 (15%) 533.7  6 (25%) 583.4  7 (25%) 636.4 8 (5%) 655.4 9 (5%) 727.0 10 (15%) >727.0

Example 7

Estolide base oil 4B (from Example 4) was subjected to distillation conditions (ASTM D-6352) at 1 atm over the temperature range of about 0° C. to about 730° C., which resulted in 9 different estolide cuts. The amount of each cut and the temperature at which each cut was recovered are reported in Table 5a.

TABLE 5a Cut (% of total) Temp. (° C.) 1 (1%) 432.3 2 (1%) 444.0 3 (3%) 469.6 4 (5%) 521.4  5 (15%) 585.4  6 (25%) 617.1  7 (25%) 675.1 8 (5%) 729.9  9 (20%) >729.9

Example 8

Estolides were made according to the method set forth in Example 1, except that the 2-ethylhexanol esterifying alcohol used in Example 1 was replaced with various other alcohols. Alcohols used for esterification include those identified in Table 5b below. The properties of the resulting estolides are set forth in Table 9.

TABLE 5b Alcohol Structure Jarcol ™ I-18CG iso-octadecanol Jarcol ™ I-12 2-butyloctanol Jarcol ™ I-20 2-octyldodecanol Jarcol ™ I-16 2-hexyldecanol Jarcol ™ 85BJ cis-9-octadecen-l-ol Fineoxocol ® 180

Jarcol ™ I-18T 2-octyldecanol

Example 9

Estolides were made according to the method set forth in Example 2, except the 2-ethylhexanol esterifying alcohol was replaced with isobutanol. The properties of the resulting estolides are set forth in Table 9.

Example 10

Estolides of Formula I, II, and III are prepared according to the method set forth in Examples 1 and 2, except that the 2-ethylhexanol esterifying alcohol is replaced with various other alcohols. Alcohols to be used for esterifictaion include those identified in Table 6 below. Esterifying alcohols to be used, including those listed below, may be saturated or unsaturated, and branched or unbranched, or substituted with one or more alkyl groups selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, isopentyl, neopentyl, hexyl, isohexyl, and the like, to form a branched or unbranched residue at the R₂ position. Examples of combinations of esterifying alcohols and R₂ Substituents are set forth below in Table 6:

TABLE 6 Alcohol R₂ Substituents C₁ alkanol methyl C₂ alkanol ethyl C₃ alkanol n-propyl, isopropyl C₄ alkanol n-butyl, isobutyl, sec-butyl C₅ alkanol n-pentyl, isopentyl neopentyl C₆ alkanol n-hexyl, 2-methyl pentyl, 3- methyl pentyl, 2,2-dimethyl butyl, 2,3-dimethyl butyl C₇ alkanol n-heptyl and other structural isomers C₈ alkanol n-octyl and other structural isomers C₉ alkanol n-nonyl and other structural isomers C₁₀ alkanol n-decanyl and other structural isomers C₁₁ alkanol n-undecanyl and other structural isomers C₁₂ alkanol n-dodecanyl and other structural isomers C₁₃ alkanol n-tridecanyl and other structural isomers C₁₄ alkanol n-tetradecanyl and other structural isomers C₁₅ alkanol n-pentadecanyl and other structural isomers C₁₆ alkanol n-hexadecanyl and other structural isomers C₁₇ alkanol n-heptadecanyl and other structural isomers C₁₈ alkanol n-octadecanyl and other structural isomers C₁₉ alkanol n-nonadecanyl and other structural isomers C₂₀ alkanol n-icosanyl and other structural isomers C₂₁ alkanol n-heneicosanyl and other structural isomers C₂₂ alkanol n-docosanyl and other structural isomers

TABLE 7 ASTM PROPERTY ADDITIVES METHOD Ex. 4A Ex. 2 Ex. 4B Color None — Light Amber Amber Gold Specific Gravity (15.5° C.), g/ml None D 4052 0.897 0.904 0.912 Viscosity - Kinematic at 40° C., cSt None D 445 32.5 65.4 137.3 Viscosity - Kinematic at 100° C., cSt None D 445 6.8 11.3 19.9 Viscosity Index None D 2270 175 167 167 Pour Point, ° C. None D 97 −30 −33 −36 Cloud Point, ° C. None D 2500 −30 −32 −36 Flash Point, ° C. None D 92 n/a (>200) n/a (>250) n/a (>286) Fire Point, ° C. None D 92 300 300 320 Evaporative Loss (NOACK), wt. % None D 5800 1.9 1.4 0.32 Vapor Pressure - Reid (RVP), psi None D 5191 ≈0 ≈0 ≈0

TABLE 8 ASTM PROPERTY ADDITIVES METHOD Ex. 3A Ex. 1 Ex. 3B Color None — Light Gold Amber Amber Specific Gravity (15.5° C.), g/ml None D 4052 0.897 0.906 0.917 Viscosity - Kinematic at 40° C., cSt None D 445 40.9 91.2 211.6 Viscosity - Kinematic at 100° C., cSt None D 445 8.0 14.8 27.8 Viscosity Index None D 2270 172 170 169 Pour Point, ° C. None D 97 −32 −40 −40 Cloud Point, ° C. None D 2500 −32 −33 −40 Flash Point, ° C. None D 92 278 286 306 Fire Point, ° C. None D 92 300 302 316 Evaporative Loss (NOACK), wt. % None D 5800 1.4 0.8 0.3 Vapor Pressure - Reid (RVP), psi None D 5191 ≈0 ≈0 ≈0

TABLE 9 Ex- am- Estimated Pour Cloud Visc. Visc. ple EN Pt. Pt. @ @ Visc. # Alcohol (approx.) ° C. ° C. 40° C. 100° C. Index 8 Jarcol™ 2.0-2.6 −15  −13 103.4 16.6 174 I-18CG 8 Jarcol™ I-12 2.0-2.6 −39  −40 110.9 16.9 166 8 Jarcol™ I-20 2.0-2.6 −42 <−42 125.2 18.5 166 8 Jarcol™ I-16 2.0-2.6 −51 <−51  79.7 13.2 168 8 Jarcol™ 85BJ 2.0-2.6 −15  −6 123.8 19.5 179 8 Fineoxocol® 2.0-2.6 −39  −41 174.2 21.1 143 180 8 Jarcol™ 2.0-2.6 −42 <−42 130.8 19.2 167 I-18T 8 Isobutanol 2.0-2.6 −36  −36  74.1 12.6 170 9 Isobutanol 1.5-2.2 −36  −36  59.5 10.6 170

Example 11

Saturated and unsaturated estolides having varying acid values were subjected to several corrosion and deposit tests. These tests included the High Temperature Corrosion Bench Test (HTCBT) for several metals, the ASTM D130 corrosion test, and the MHT-4 TEOST (ASTM D7097) test for correlating piston deposits. The estolides tested having higher acid values (0.67 mg KOH/g) were produced using the method set forth in Examples 1 and 4 for producing Ex. 1 and Ex. 4A (Ex.1* and Ex.4A* below). The estolides tested having lower acid values (0.08 mg KOH/g) were produced using the method set forth in Examples 1 and 4 for producing Ex. 1 and Ex. 4A except the crude free-acid estolide was worked up and purified prior to esterification with BF₃.OET₂ (0.15 equiv.; reacted with estolide and 2-EH in Dean Stark trap at 80° C. in vacuo (10 torr abs) for 12 hrs while continuously being agitated; crude reaction product washed 4×H₂O; excess 2-EH removed by heating washed reaction product to 140° C. in vacuo (10 torr abs) for 1 hr) (Ex.4A# below). Estolides having an IV of 0 were hydrogenated via 10 wt. % palladium embedded on carbon at 75° C. for 3 hours under a pressurized hydrogen atmosphere (200 psig) (Ex.4A*H and Ex.4A#H below) The corrosion and deposit tests were performed with a Dexos™ additive package. Results were compared against a mineral oil standard:

TABLE 10 Ex. 1* Ex. 4A* Ex. 4A*H Ex. 4A# Ex. 4A#H Standard Estolide Estolide Estolide Estolide Estolide Acid Value — ~0.7 0.67 0.67 0.08 0.08 (mg KOH/g) Iodine Value — ~45 16 0 16 0 (IV) HTCBT Cu 13 739 279 60 3.2 13.6 HTCBT Pd 177 11,639 1,115 804 4.93 243 HTCBT Sn 0 0 0 0 0 0 ASTM D130 1A 4B 3A 1B 1A 1A MHT-4 18 61 70 48 12 9.3

Example 12

“Ready” and “ultimate” biodegradability of the estolide produced in Ex. 1 was tested according to standard OECD procedures. Results of the OECD biodegradability studies are set forth below in Table 11:

TABLE 11 301D 28-Day 302D Assay (% degraded) (% degraded) Canola Oil 86.9 78.9 Ex. 1 64.0 70.9 Base Stock

Example 13

The Ex. 1 estolide base stock from Example 1 was tested under OECD 203 for Acute Aquatic Toxicity. The tests showed that the estolides are nontoxic, as no deaths were reported for concentration ranges of 5,000 mg/L and 50,000 mg/L.

Example 14

Estolides are made according to the method set forth in Example 1.50 g of the resulting estolides and elemental sulfur (1 g) are added to a 2 liter, 4 neck flask fitted with a stirrer, thermowell, gas inlet tube, and Dean Stark trap with reflux condenser. The contents are heated to 150° C. for 3 hours while sparging with nitrogen at 0.75 cubic feet per hour. The contents are permitted to cool to room temperature, and are filtered to provide sulfurized estolides.

Example 15

Sulfurized estolides are made according to the method set forth in Example 14, except the sulfurization is performed separately on each of the estolides made according the methods set forth in Examples 2, 3 (3A and 3B), and 4 (4A and 4B).

Example 16

Estolides were made according to the method set forth in Example 1, and processed according to the distillation conditions of Example 3 to provide estolides of Ex. 3A and 3B. Ex. 3A estolides (1.0 eq.) were added to a round bottom flask, cooled to 5° C., along with aqueous H₂O₂ (4 eq.) and formic acid (4.1 eq.). The mixture was stirred vigorously and allowed to warm to room temperature. Stirring of the reaction mixture was allowed to continue for a total of 72 hours. The reaction mixture was then extracted in a separatory funnel with hexanes and washed with an aqueous sodium sulfite solution. The organic layer was washed several more times with deionized water and dried over magnesium sulfate (anhydrous), and filtered. The solvents were then removed in a rotary evaporator to yield epoxidized estolides.

Example 17

Estolides were made according the method set forth in Example 1, except the free-acid estolide intermediate was isolated prior to esterification with 2-EH. Instead, the water-washed free-acid estolide intermediate was filtered through a 1μ filter and isolated. The isolated free-acid estolide was then subjected to distillation conditions (Myers 15 Centrifugal Distillation) to remove any unreacted fatty acid starting materials to provide a purified free-acid estolide product (Ex. 17FA).

Estolides of Example 17FA, Example 3 (3A, 3B), and Example 16 (epoxidized Ex. 3A estolides) were separately blended with virgin PVC powder (polyvinyl chloride homopolymer, OxyVinyls® 220F, Occidental Petro. Corp.). The plasticized blends were transferred to an Extrusion Plastometer (Tinius Olsen Model MP987). The blends were then heated to 200° C., held for 5 minutes, and then extruded into strands for characterization. Results of the extrusion are set forth below in Table 12:

TABLE 12 Plasticized Strand Blend No. Estolide (%) PVC % Characteristics Pass/Fail 17A Ex. 17FA (15) 85 Non-continuous and Fail fragmented 17B Ex. 3A (15) 85 Non-continuous and Fail fragmented 17C Ex. 3B (15) 85 Non-continuous and Fail fragmented 17D Ex. 16 (epox. Ex. 85 Continuous and Pass 3A) (15) uniform

Example 18

Virgin PVC (OxyVinyls® 220F) and plasticized blend No. 17D of Example 17 were subjected to Differential Scanning calorimetry (DSC) using a Mettler DSC 820 with TSO 801RO Sample Robot to determine glass transition temperature (Tg, ° C.). Results of the DSC testing are set forth below in Table 13:

TABLE 13 Sample Tg (° C.) Depression of Tg Virgin PVC 85 — Blend No. 17D 64 25%

Example 19

Free-acid estolides are prepared according to the method set forth in Example 17 (Ex. 17FA). The free acid estolide product is further distilled to provide a primary distillate having a lower EN (Ex. 19A) and a secondary distillate having a higher EN (Ex. 19B).

Example 20

Epoxidized estolides are made according to the method set forth in Example 16, except the estolides of Example 3A are replaced and the epoxidation is repeated separately on each of the estolides made according the methods set forth in Example 1, Example 2, Example 3B, Example 4 (4A, 4B), Example 17 (Ex. 17FA), and Example 19 (19A, 19B).

Example 21

Plasticized blends are prepared and tested according to the method set forth in Example 17, except the estolides set forth therein are replaced with those described in Example 20.

Example 22

Estolides were prepared according to the methods set forth in Example 17 (Ex. 17FA), Example 3 (3A, 3B), and Example 16 (epoxidized Ex. 3A), and tested for stability using thermogravimetric analysis (TGA). The TGA was performed using a Mettler TGA 850 with TSO 801RO Sample Robot, in which each sample was initially heated from 30° C. to 165° C. at a rate of 20° C./min, and then held at 165° C. for 30 min. Results of the TGA testing are set forth below in Table 14, where % weight loss (from commencement of testing) is reported at separate time intervals:

TABLE 14 Ex. 8 min. 15 min. 25 min. 37 min. 17FA ~0.3% ~0.6% ~0.8% ~0.9%  3A <0.1% ~0.6% ~1.4% ~2.2%  3B   0%   0%   0%   0% 16 (epox. 3A) ~0.6% ~1.1% ~1.4% ~1.6% 

The invention claimed is:
 1. At least one compound of Formula I:

wherein W¹, W², W³, W⁴, W⁵, W⁶, and W⁷, independently for each occurrence, are selected from —CH₂—, —CH═CH—, —CHR₅—, and

provided that at least one of W¹, W², W³, W⁴, W⁵, W⁶, or W⁷ is —CHR₅— or

R₅ is selected from —S_(v)R₆, wherein v is an integer selected from 1 to 8 and R₆ is selected from hydrogen and an estolide residue; T is S; z is an integer selected from 0 to 15; p is an integer selected from 0 to 15; q is an integer selected from 0 to 15; x is, independently for each occurrence, an integer selected from 0 to 20; y is, independently for each occurrence, an integer selected from 0 to 20; n is equal to or greater than 0; and R₂ is selected from hydrogen and optionally substituted alkyl that is saturated or unsaturated, and branched or unbranched, wherein each fatty acid chain residue of said at least one compound is independently optionally substituted.
 2. The at least one compound according to claim 1, wherein at least one of W¹, W², or W³ is —CHR₅— or


3. The at least one compound according to claim 1, wherein W³ is —CH₂—.
 4. The at least one compound according to claim 1, wherein W¹ is —CH₂—.
 5. The at least one compound according to claim 1, wherein W² is selected from —CHR₅— and


6. The at least one compound according to claim 5, wherein W² is selected from —CHR₅—, and R₅ is selected from —S_(v)R₆.
 7. The at least one compound according to claim 1, wherein R₆ is an estolide residue.
 8. The at least one compound according to claim 1, wherein v is an integer selected from 1 and
 2. 9. The at least one compound according to claim 5, wherein W² is selected from


10. The at least one compound according to claim 1, wherein z is an integer selected from 2 to
 8. 11. The at least one compound according to claim 10, wherein z is
 6. 12. The at least one compound according to claim 1, wherein p is an integer selected from 1 to
 5. 13. The at least one compound according to claim 12, wherein p is
 1. 14. The at least one compound according to claim 1, wherein q is an integer selected from 1 to
 8. 15. The at least one compound according to claim 1, wherein q is selected from 0 and
 1. 16. The at least one compound according to claim 1, wherein q is an integer selected from 5 and
 6. 17. The at least one compound according to claim 1, wherein W² is selected from —CHR₅—, R₅ is selected from —S_(v)R₆, and p is an integer selected from 1 and
 2. 18. The at least one compound according to claim 17, wherein v, independently for each occurrence, is an integer selected from 1 and
 2. 19. The at least one compound according to claim 1, wherein W² is selected from

and p is
 1. 20. The at least one compound according to claim 1, wherein the compound is selected from at least one compound according to Formula III:


21. The at least one compound according to claim 1, wherein n is an integer selected from 0 to
 12. 22. The at least one compound according to claim 21, wherein n is an integer selected from 0 to
 8. 23. The at least one compound according to claim 22, wherein n is an integer selected from 0 to
 6. 24. The at least one compound according to claim 1, wherein n is equal to or greater than
 1. 25. The at least one compound according to claim 1, wherein x+y is, independently for each chain, an integer selected from 13 to
 19. 26. The at least one compound according to claim 25, wherein x+y is, independently for each chain, an integer selected from 13 to
 15. 27. The at least one compound according to claim 1, wherein x+y is 15 for at least one chain.
 28. The at least one compound according to claim 1, wherein R₂ is a branched or unbranched C₁ to C₂₀ alkyl that is saturated or unsaturated.
 29. The at least one compound according to claim 1, wherein R₂ is selected from methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decanyl, undecanyl, dodecanyl, tridecanyl, tetradecanyl, pentadecanyl, hexadecanyl, heptadecanyl, octadecanyl, nonadecanyl, and icosanyl, which are saturated or unsaturated and branched or unbranched.
 30. The at least one compound according to claim 28, wherein R₂ is selected from C₆ to C₁₂ alkyl.
 31. The at least one compound according to claim 30, wherein R₂ is 2-ethylhexyl.
 32. The at least one compound according to claim 1, wherein R₂ is hydrogen.
 33. The at least one compound according to claim 1, wherein R₂ is an unsubstituted alkyl that is saturated or unsaturated, and branched or unbranched.
 34. The at least one compound according to claim 20, wherein z is 6 and q is an integer selected from 0 to
 6. 